THE
ANATOMY OF THE BARK
OF
, Libocedrus,
AND
Dacrydium
Phyllocladus
IN
NEW ZEALAND
A
sis
submitted In
1 fulfilment
of the requirements for the Degree
of
Master of Fores
Science
in the
University of C
by
Lek-Lim CHAN
University of Canterbury
1982
Through work, man must earn his daily
bread and contribute to the continual
advance of science and technology
and, above all, to elevating unceasingly
the cultural and moral level of the
society within which he lives in
community with those who belong to the
same family.
And work means any
activity by man, whether manual or
intellectual, whatever its nature or
circumstances;
it means any human
activity that can and must be
recognized as work, in the midst of
all the many activities of which man
is capable and to which he is
predisposed by his very nature, by
virtue of humanity itself.
Pope John Paul II,
Laborem Exercens,
Encyclical letter, 1981,
On human work.
For the people of New Zealand,
opportunity
In appreciation of
Of pursuing my
studies here
In this beautiful 1
And,
Especially for the
s of
Newman Society of
The University of Cante
In appreciation of the
Support and encouragement
During my varsity days,
Particularly the time when
This work was being undertaken.
TABLE OF CONTENTS
Page
i
Abstract
Abbreviations
I
iii
1
Introduction
The New Zealand Gymnosperms
3
II
Terminology
4
III
Materials and Methods
8
IV
V
Materials
8
Methods
9
12
Results
(1)
Agathis australis
(2 )
Libocedrus bidwillii Hook.
( 3)
L.
(4 )
Dacrydium kirkii
(5)
D.
biforme
(6 )
D.
bidwillii
( 7)
D.
laxifolium
(8)
D.
cupressinum Lamb.
41
( 9)
D.
intermedium Kirk.
44
(10)
D.
colensoi
(ll)
Phyllocladus alpinus Hook.
(12)
Phy.
glaucus Carr.
(13 )
Phy.
trichomanoides
14
Salisb.
plumosa
£.
20
(Don. ) Sargent.
23
F. MuelL ex Parl.
26
(Hoole. ) Pilger.
30
Hook. £. ex Kirk.
Hook. £.
Hook.
34
37
48
£.
52
56
D. Don in Lamb
60
Discussion
64
Acknowledgements
78
References
79
Literature cited
79
Other literature consulted
84
Appendices
85
l
ABSTRACT
The anatomy of the bark of
Dacrydium
Agathis, Libocedrus,
and Phyllocladus in New Zealand is described.
Samples were collected from local areas in
Canterbury, Buller and Northland, and examined by optical
and scanning electron microscopy.
In Libocedrus species, the sclerenchyma consists of
thin and thick-walled fibres. In all other species, the
sclerenchyma comprises fibres and sclereids.
However,
sclerenchyma is quite rare or sometimes absent in Dacrydium
laxifolium.
Crystals occur in the lumina and also in the
wall (in the region of the middle lamella) of some phloem
cells.
Resin canals are present in the phloem, primary
cortex and phelloderm of Agathis australis and in the primary
cortex of all the three species of Phyllocladus.
Land T-shaped parenchyma cells were found to be
cOmmon in the phloem of
Dacrydium cupressinum.
These cells
lie partly in the ray system and partly in the axial
system, and are filled with tannin.
common in the phloem in
Phellem cells in
Trabeculae were very
Libocedrus bidwillii.
Libocedrus
walled and appear flimsy.
species are very thin-
In Agathis australis,
the phellem
cells are mostly thin-walled, with the outer 1-3 layers
being thick-walled.
glaucus
Those in Dacrydium cupressinum, Phyllocladus
and Phy. trichomanoides are all thin-walled.
Phellem
of the other six Dacrydium species consists of thin-walled
cells and also cells with an inner tangential wall that is
thicker than the outer tangential wall.
In three species,
this inner tangential wall is sclerified and in the other
ii
three species, it is non-polylamellate but possesses
cone-shaped structures, protruding into the lumina.
This latter feature is also shared by phellem cells in
Phyllocladus alpinus.
Minute crystals were found to be
very abundant in the walls of phelloderm cells under
lenticels, in most species.
iii
ABBREVIATIONS
The
llowing abbreviations will be used In
text:
LM
light microscope or light micrograph
RLS
radial longitudinal section
SEM
scanning electron microscope or scanning
ctron micrograph
TLS
tangential longitudinal section
TS
transverse section
1
I
I
INTRODUCTION
Information on the anatomy of bark is relatively
scanty, compared to that of wood.
Only a few extens
studies have been made in the past (e,g. Chang 1954a,b;
Chattaway 1953, 1955a,b,c,d,e, 1959;
Outer 1967;
Bamber 1959, 1962;
Howard 1971, 1977;
Den
Srivastava 1963b;
Richter 1980;
investigated
workers
Zahur 1959;
Datta 1981).
Other
anatomy of certain
s on
a smaller scale, where perhaps only one spec
genus
a
been studied (e.g. Schneider 1945;
1963a;
Srivastava & O'Br
1966;
Srivastava 1970;
Bramhall & Kellogg 1979; Esau 1934, 1938).
have worked on various as
Evert 1960,
Yet others
s of or related to bark
structure and function (e.g. Thomson & Sifton 1925;
Sinz 1925;
Evert 1963bi
Esau et al 1962;
Shah & James 1968;
Parameswaran 1975a,bi
& Krahmer 1976;
Srivastava 1963a;
Esau 1968;
Crist 1972;
Goldschmid & Folsom 1975;
Nanko et al 1977).
Litvay
Esau (1969) has
reviewed and summarized all the work
had been under-
on the phloem, up till that time.
There has
a few anatomical
s carried out
on bark in either indigenous or exotic
Zealand.
barks
Craddock (1932a) made a det
(rinds) of Podocarpus dacrydioides,
s in New
study of the
P. spicatus,
P. ferrugineus, P. totara, Dacrydium cupressinum
and
D. colensoi.
In the same work, rough studies were also made on the
other New Zeal
species of the Podocarpaceae family.
He also descr
the origin of the periderm in all the
species examined.
However, only an abstract of this work
2
was published (Craddock 1932b).
Robinson & Grigor (1963)
examined the origin of the periderm in some New Zealand
plants including n
gymnosperms, namely
um biforme, D. bidwillii,
, P. nivalis, P. totara,
tr ichomanoides
D. cupressinum, Phyllocladus alpinus,
australis.
Except for
ies.
Craddock
A. australis,
(1932a,b) had examined the orig
and
of the per
in these
Barnett (1974a,b) studied the structure of
parenchyma cel
Is in the
and differentiating sieve
secondary phloem of Pinus radiata.
Patel (1975) worked on
the bark of Pinus radiata, Pinus
and Pseudotsuga menziesii.
Kucera & Butterfield (1977) investigated
the bark of New Zealand Phyllocladus spec
resin canals
s, but the
general anatomy of these barks was not examined.
Patel
(pers. comm.) is carrying out preliminary anatomical work
on the bark of New Zealand beeches.
made some
Dr. Shigematsu has
s on the anatomy of the
the podocarpus species but
of most of
s observations have not been
published (Dr. J.M. Harris, pers. comm.).
Chan (1979)
examined the barks of all the Podocarpus species in New
Zealand and the work is
to be published (Chan & Ellis,
ln preparation, 1982).
Detailed anatomical work on the wood of New Zealand
gymnosperms is complete (Patel 1967a,b, 1968a,b; Meylan &
Butterf
Id
1978) but information on the anatomy of their
bark is lacking.
For this reason, it was cons
appropriate to follow on from the earlier work (Chan 1979),
continuing to examine the anatomy of the barks of the
other New Zealand gymnosperms.
3
THE NEW ZEALAND GYMNOSPERMS
Twenty spec
s of gymnosperms belonging to five
genera occur naturally in New Zealand.
Table 1 shows
all the genera and species.
Family
Genera and species
Common name
Araucariaceae
Agathis australis
kauri
Libocedrus bidwillii
plumosa
pahautea, cedar
kawaka
podocarpus
P.
P.
P.
P.
P.
P.
kahikatea
matai
miro
snow totara
totara
Hall's totara
needle-leaved totara
Cupressaceae
L.
Podocarpaceae
Table 1:
dacrydioides*
spicatus*
ferrugineus*
nivalis
totara
hallii
acutifolius
Dacrydium kirkii
D.
biforme
D.
bidwillii
D.
laxifolium
D.
cupressinum
intermedium
D.
D.
colensoi
monoao
pink pine
bog or mountain pine
pygmy pine
rimu, red pine
yellow silver pine
silver pine
Phyllocladus
Phy.
glaucus
Phy. trichomanoides
mountain toatoa
toatoa
celery pine, tanekaha
Genera and species of all gymnosperms in New Zealand.
*
to De Laubenfels' classification (1969),
would be renamed Dacrycarpus dacrydioides,and
and P.
would be renamed Prumnopitys
ferrugineus respectively.
Details on the spec
s and their geographic
tion are given in Allan (1961).
stribu-
Agathis australis, Libocedrus
bidwillii, L. plumosa, Dacrydium kirkii, D. cupressinum, D. intermedium,
D. colensoi, Phyllocladus
trees over 15 m tall.
and
Phy. trichomanoides
D. biforme and Phy.
or small trees up to 10 and 9 m tall respec
are all
are shrubs
ly.
D. bidwillii
is a spreading or erect shrub up to 3.5 m tall while
D. laxifolium
is a
slender, flexuous
trate to sub-lianoid shrub with very
ets (Allan 1961) .
4
II. TERMINOLOGY
The Society of American Foresters (1958) de
s
bark as 'the tissues of stem, branch and root outs
cambium layer',
It
the
defines inner bark as 'the
cambium
physiologically act
layer of tissues between
and the last formed
iderm', and outer bark as 'the layer
of dead tissue
formed peridermt,
Anatomists
bark as 'a
corky nature, outs
a
last-
The International Associ
(I.A.W.A.)
no~techial
of Wood
(1964), on the other hand defines
term used to cover all the tissues
outside the
em cylinder' r secondary phloem as 'normally,
the part of
bark formed by the cambium', and rhytidome
as 'the phel
and tissues isolated by it;
enclosing
of cortical or phloem
technical term
often
ssues;
the outer bark'.
bark' defined by the
The '
a
of American
Foresters (1958) is thus synonymous with the 'secondary
phloem' defined by the I.A.W.A.
(1964).
of Ibark' by the I.A.W.A. seems to include the
defin
vascular
ium while the definition by the Society of
American Foresters excludes it.
American Foresters 1958) does not
while 'rhytidome '
phel
di
'Outer bark'
(Society of
lude the last-formed
(I.A.W.A. 1964) includes the
of the last-formed per
In this work, the definit
of
However, the
can Foresters (1958) will
am in TS (Fig. lA) will
anations.
of 'bark' by the Soc
followed.
A schematic
the following
The word 'phloem' will be used to mean
phloem'
(I.A.W.A. 1964) or 'inner bark'
(Socie
5
of American Foresters 1958).
'Conducting phloem' refers
to that part of the phloem close to the vascular cambium
where the sieve cells are still functioning in conduction,
and 'living bark' designates that part of the bark to the
outside of the vascular cambium up to and including the
last-formed periderm.
'outer bark'
'Rhytidome'
1S
synonymous with
(Society of American Foresters 1958), and
'periderm' or 'living periderm' will be used to denote the
last-formed periderm.
In a young stem, the outer protective
layer is the epidermis and cuticle.
Eventually, parenchyma-
tous cells in the epidermis, sub-epidermis or primary cortex
become meristematic, forming a phellogen producing phelloderm
(centripetally) and phellem or cork (centrifugally).
Often
the development of one phellogen is followed by others deeper
in the stem (Cutter 1969).
In mature stems, the phellogen
is usually derived from some phloem parenchyma cells.
Tissues isolated from the living bark by the last-formed
periderm die and become part of the rhytidome.
Thus the
rhytidome comprises old periderms and old phloem.
If
alternate layers of dead periderms and phloem persist on
the stem and are not exfoliated, the rhytidome may consist
of several to many layers of old periderm and phloem.
In gymnosperms, the phloem usually consists of
axially oriented sieve cells, parenchyma, sometimes fibres
or sclereids or both and radially oriented ray parenchyma.
Some parenchyma cells are physiologically associated with
sieve cells and are usually regarded as comparable to the
companion cells of angiosperm phloem (Esau 1969;
1977) .
Evert
Such parenchyma cells are referred to as albuminous
cells or strasburger cells, and are commonly not
6
ontogenetically related to their associated sieve cells
Parenchyma cells, both axial and ray,
(Evert 1977).
often undergo secondary deve
, often becoming
sclerenchymatous in nature (see next paragraph).
Sclerenchyma is cornmon in bark and usually consists
of fibres or sclereids or both, but may be totally absent.
The origin of the cell is
s used to distinguish
between the two cell types (Esau 1969).
meristematic cells while
are cells derived
loped from originally matured
sclereids are cells
parenchyma.
Thus, fibres
However, in practice the separation of
two categories of cells is often not definitive.
the distinction
se
When
a fibre and a sclereid is
difficult, the term fibre sclereid may be used (Esau 1969) .
Parameswaran (1980) has redefined the cell
s of
phloem sclerenchyma to avoid the use of the term
sclereid, thus
ontogeny.
bre~
ing with the question of
He uses
term 'sclerotic phloem
for cells with polylamellate lignified walls having an
elongated
, exhibiting apical intrusive growth.
He
further introduces the term 'lignified parenchyma' for
cells with
derived
ck, lignified but non-polylamellate walls,
mature parenchyma with a form
isodiametric or corresponding to the length
cells and lacking apical intrusive growth.
term'
three 1
ther
the original
He retains the
fibres' for cells normally provided with the
s of secondary wall (in addi
lamella/primary wall), derived from
the vascular cambium with an elongated
apical
is
trusive growth.
to the middle
iform initials of
and exhibiting
Sclereids are cells with lignified
7
polylamellate walls, derived from living parenchymatous
cells with a form that is isodiametric or slightly to
considerably elongated and lacking apical intrus
growth (Parameswaran 1980).
8
MATERIALS AND METHODS
I I 1.
MATERIALS
The barks of all the species of Agathis, Libocedrus,
Dacrydium
and
Phylloc1adus
were studied.
The number of
trees/plants and the locality where the samples were
gathered are given in Table 2.
Species
Locality
No. of trees/
plants
-----------------------------Agathis australis
Puketi SF
3
Libocedrus bidwillii
Inangahua West SF
3
Ornahuta SF
3
Puketi SF
3
L.
plumosa
Dacrydium kirkii
D.
biforme
Inangahua West SF
3
D.
bidwi11ii
Burnt Face,
Bealey SF
3
D.
laxifolium
Arthur's Pass
National Park
3
D.
cupressinum
Ianthe SF
3
Inangahua lilest SF
2
Maimai SF
1
Inangahua West SF
2
Mokihinui SF
3
Maimai SF
1
Inangahua West SF
2
Mokihinui SF
1
Maimai SF
2
Inanganua West
1
Puketi SF
3
Puketi SF
3
D.
D.
intermedium
colensoi
Phyllocladus alpinus
Phy.
glaucus
Phy. trichomanoides
..-~
SF = State Forest
Table 2:
The locality and number of trees/plants collected at
each locality.
9
For each species, at least three trees/plants
were selected.
A
imen was collected from each of
two opposite ends of a diameter of the tree stem at
breast height.
In
case of Dacrydium bidwillii and
D. laxifolium, a short section of a stem was
a point about 30 cm
at
the stem/root junction of each
shrub.
METHODS
Specimens were obtained by using a brace fitted
with a 38 mm diameter hole-saw and a mandrel.
chisel and hammer were used to break
after ho
-sawing.
A small
specimens off
Sometimes the samp
were removed
directly with chisel and hammer without
hole-saw,
particular
the use of
in the case of
Libocedrus
the hole-saw tends to shatter the bark.
specimen was removed, a pitchy mater
for seal
possible
pruning wounds) was appl
o~
pathogens entering
specimens were immediate
After each
1 (usually used
to minimise the
tree.
fixed l.n 5%
glutaraldehyde in 0.025 M phosphate buffer (see Appendix
1 for
ls) and left in the
However, the specimens of
until sectioning.
Dacrydium cupressinum
from
Ianthe State Forest were fixed in Formalin-Acetic acidAlcohol as specified by Purvis et al (1966).
At the time
of collection, the diameter over bark at the point of
tion was measured.
Observations were made using the light (LM) and
s
a
electron (SEM) microscopes.
carried out.
Macerations were
10
For light microscopy, sections (ca. 30
~m
in
thickness) were cut without embedding or further treatment,
by a Reichert 'OrnE' sledge microtome with a shape II knife
from blocks of bark not more than 7 mm x 5 mm on the
cutting face.
From each specimen, transverse sections
(TS) , radial longitudinal sections (RLS) and tangential
longitudinal sections (TLS) were prepared.
The cutting
and knife angles of the knife were found to be critical
for different barks,
Is
which are given in Table 3.
The shapeness of the microtome knife was also very
tical. Sections were picked up from the microtome knife
with a fine hair brush wetted with 25% alcohol and then
left in a pet
-dish of 45% alcohol, until stained.
Specimens were double-stained with safranin and fast
green.
The full schedu
is given in Appendix II.
Macerations were carried out on specimens cut to
about 1-2 mm thickness and heated in a solution of equal
amounts of glac
acetic acid and 20 volume hydrogen
peroxide in test-tubes in a boiling water bath for about
1 2 hours.
The tissue was stained with 1.5% aqueous
safranin for a
minutes, then washed with a few drops
of water, teased out and mounted in a few drops of Karo
syrup (a water-soluble mounting medium) •
Slide specimens were examined under the Nikon Biophot
microscope and photomicrographs recorded on Ilford FP4
1m.
For SEM observations, the specimens were prepared
by hand, following the method outlined by Exley et al
(1974, 1977).
It was found necessary to put the specimens
through an increasing concentration alcohol series (see
11
Appendix
III
for de
drying.
For examination of wall structure, soaking the
Is) and finally critical point
specimens in 5% sodium hyochlorite solution before the
alcohol serles was requi
debris.
to remove cell contents and
Dried specimens were coated with gold in the
Polaron Diode Sputtering System E500 and examined in a
Cambridge Stereos can 600 scanning electron microscope,
and photomicrographs recorded on FP4 film.
Orientation
of sections
Species
Knife
angle
Cutting
angle
(0)
(0)
Agathis australis
TS/RLS
TLS
8
6-8
10
10
Libocedrus bidwillii
TS/RLS/TLS
6-7
10
TS
RLS/TLS
6-6.5
6
10
10
Dacrydium kirkii
TS/RLS
TLS
7
7-8
10
10
D.
biforme
TS/RLS/TLS
8
10
D.
bidwillii
TS/RLS/TLS
8
10
D.
laxifolium
TS/RLS/TLS
8
10
D.
cupressinum
TS
RLS
TLS
8
6-10
10
10
10
L.
plumosa
9
D.
intermedium
TS/RLS/TLS
7.5
10
D.
colensoi
TS/RLS
TLS
7-8
7-9
10
10
TS
RLS
TLS
8
7-8
7
10
10
20
8
10
8
7-8
10
10
alpinus
Phy.
TS/RLS/TLS
Phy. trichomanoides
TS/RLS
TLS
Table 3:
Knife and cutt
angles of the microtome knife
bark of different species.
for sect
12
IV.
RESULTS
Results will be presented species by species.
The format of the presentation in each species is:
(1)
diameter and living bark thicknesses of the
specimens from each tree,
(2)
phloem description, comprising (a) general description
of the arrangement of cell types,
(c)
parenchyma cells,
(e) fibres,
(b) sieve cells,
(d) phloem rays,
(f) phloem sclereids, and (g) phloem
resin canals, if present,
(3)
description of the primary cortex, if present in any
of the specimens,
(4 )
description of the
iderm, comprising '(a) phelloderm,
and (b) phellem,
(5)
photomicrographs of
barki
a low power view (x60)
of the bark, from the vascular cambium to at least
the periderm, is included among the other photomicrographs for each species to give a general
impression.
A few clarifications at this point are appropriate:
(1)
the approximate size of crystals is given as a length
which refers to the greatest length (or diameter)
across the crystal;
(2)
the word 'prismatic' or 'prism' for crystal shapes
refers to a thin flat crystal with two parallel
surfaces (e.g. a hexagonal prismatic crystal as
shown in Fig. IB)
i
13
(3)
in photomicrographs showing TS or RLS, the
outside of the stem is either to the left or
top of the micrographs unless otherwise stated;
(4)
in the captions of photomicrographs of sieve
areas, the term 'vertical diameter' refers to the
shortest distance between two parallel horizontal
lines demarcating the limits of the sieve area to
the top and bottom, and 'horizontal diameter'
refers to the shortest distance between two
parallel vertical lines demarcating the limits
of the sieve area to the left and right
(see Fig. lC).
Fig. 1
Explanatory Diagrams
A.
Schematic
agram showing the general
arrangement of bark tissues in TS.
(See text, under 'Terminology' for
explanations) .
B.
Diagram showing a crystal described as
'hexagonal pri
' in shape.
c.
Diagram of a
area showing what
vertical and horizont
diameters
refer to.
1
0
fl.~
(1)'<
Ii rt
f-J.
b"o.
~(I)
Dead
phloem
PI 0
Ii S
t
!
1
t1
,
Periderm
f-Jo
.q
f-J.
Phloem
(Inner bark)
::1
to
b"
PJ
Ii
7i"'
Cambiwn
A
(Wood)
L
Horizontal
diameter -'~
c
B
. 1
14
S
australis
sb.
Specimens were collected at breast height. The
ameters and living bark thicknesses of the
are as follows:
Diameter
(em)
Location of trees
Living bark
thickness (em)
(1)
Puketi State Forest
64.8
1.4
(2)
Puketi State Forest
154.0
2.3
(3 )
Puketi State Forest
l19.5
2.0
(4)
Staff Club grounds,
University of
Canterbury
34.8
1.0
The phloem comprises sieve cells, axial and ray
parenchyma, fibres and sclereids.
present (Fig. 2,3).
cells,
each
Resin canals are
Near the vascular cambium, sieve
al parenchyma and fibres appear scattered amongst
(Fig.6D).
0
About 1.0-1.3 mm from the vas
ar
cambium (the width of the conducting phloem), sclereids and
resin c
s begin to
(Fig. 2A).
Sclereids are
distributed randomly, tending to be in
non-scleri
1 rows between
rays.
Sieve cells appear rectangular in TS.
crystals (> 20
~m
long), mostly hexagonal
shape, occur in some sieve
phloem.
smatic in
in the non-conducting
Most sieve cells are crushed by sc
the outside.
Sieve areas are about 8-18
~m
(Fig. 6G) mostly on the radial wall in single
Axial parenchyma cells are isodiametric
rectangular
RLS and TLS.
Large
reids towards
diameter
leo
TS,
Some parenchyma cells are
filled with tannin while others contain large
tals
15
(> 20 ~m
long) , mostly hexagonal prismatic in shape
(Fig. 6E).
In the immediate proximity of the vascular
cambium, the parenchyma mother c
1 divides, often
forming walls in the radial longitudinal plane and also
in the transverse plane, thus giving two strands
parenchyma cells that are ontogenetically related.
sometimes
transverse wall is laid down obl
giving rise to abnormally-shaped parenchyma in the initial
stages (F
. 6F).
In the non-conducting phloem, some
parenchyma (especially those without tannin contents)
become sclereids, growing to many times the
size (Fig. 2,3).
inal
In the outer part of the phloem, the
~on
parenchyma cells shorten in the longitudinal
(Fig.
)
planes
In regions where a resin canal is
f
thus becoming almost isodiametric in all
stined to
be formed, the axial parenchyma cells divide repeatedly
with ray parenchyma cells in the
(Fig. 7G).
The cells in the centre eventually undergo
the canal, other cells forming the epithe
sis forming
urn.
Phloem rays are uniseriate, occasionally part-biseriate
and are 2-16 cells high (rarely one;
The cells are round
up to 27 counted).
TLS near the vascular cambium (Fig. 6F),
rectangular in TS and rectangular to sli
ly rhombic in RLS.
Towards the phelloderm, most of the cells become slightly
elliptical in TLS, some dilating extens
ly appearing
isodiametric in all planes or slightly elongated in the
horizontal tangential direction (Fig. 3C).
the vascular cambium where a resin
formed, the ray
In areas near
is destined to be
ls divide repeatedly together with axial
parenchyma cells, forming the canal as described above.
16
In the non-conducting phloem, some ray cells sclerify,
growing irregularly to many times their original size.
Fibres are rectangular to round in TS (Fig. 6D). Their
walls are birefringent, thick but non-lignified.
However,
some fibres near the phelloderm have lignified walls,
especially those immediately adjacent to sclereids.
lumina are small and almost indistinct.
up of three main lamellae:
The
The wall is made
two thin lamellae on the outside
and one very thick lamella on the inside (Fig. 7A,B).
Phloem sclereids are developed from some ray and axial
parenchyma and are very abundant (Fig. 2,3).
Their shape is
irregular but tend to be slightly elongated, oriented in the
longitudinal direction.
Sclereid walls are polylamellate,
lignified and birefringent.
Most sclereids have large empty
lumina (Fig. 2,3,7C,E).
Resin canals begin to form about 1.0-1.3 mm from the
vascular cambium, from ray and axial parenchyma cells which
divide repeatedly (Fig. 7G).
lysis of the central cells.
175-200
~m
in diameter
1S
The canal opens up with the
Eventually a canal about
formed (Fig. 7F, 8A).
Resin canals
in the phloem are only in the axial direction, do not seem to
be connected to each other and tend to occur in tangential
rows (Fig. 8B).
Canals within each tangential row are
spaced about 375
~m
or greater distances apart.
The primary cortex persists for a long time on the stem.
Cortical cells are isodiametric to rectangular (with axes in
the tangential horizontal direction) in TS and TLS, and
isodiametric in RLS.
about 100-250
~m
A number of lysigenous-type resin canals,
in diameter, are present in the cortex,
seemingly traversing in the axial direction and do not seem
to anastomose.
Some of the cells become sclerified, mostly
with large empty lumina (Fig. 6C), expanding only to a few
17
times the original size.
Cortical sclereids tend to occur
as tangential bands or groups.
The periderm consists of about 4S-6S layers of phellem,
one layer of phellogen and about 2S-3S layers of phelloderm.
In younger sterns
cortex is still
cortical cells.
(probably < 80 cm diameter), where the
sent, the phellogen is derived from
In older sterns (probably> 100 cm diameter) ,
the phellogen seems to arise in the phloem.
The phelloderm cells produced by phellogen derived
from cortical cells appear rather narrowly rectangular in
TS (Fig. 4E) and TLS (with long axes oriented horizontally)
and isodiametric in RLS (Fig. 4A,B,D, SE).
The first 2-4
layers of cells closest to the phellogen all have thin walls
(Fig.
, 6A) and tannin contents.
The walls, except for
the end walls, eventually become thickened but not lignified
nor polylamellate (Fig. 4B,D, 6A).
Some of the phelloderm
cells become sclerified (Fig. SE) and grow irregularly to
a few times larger than the original cells (Fig. SH), mostly
with large
stinct lumina (Fig. 6C).
Other phelloderm
cells expand without sclerification, becoming rectangular to
isodiametric, resembling cortical cells.
very few of the cells contain tannin.
Eventually, only
The phelloderm cells
are sometimes difficult to distinguish from the cortical
cells.
Lysigenous-type resin canals of about 100-lSO
diameter (Fig. 6A) are scattered in the phelloderm.
~m
Some
of them form anastomoses, the horizontal branches being more
common.
The phelloderm cells in older stems (i.e. produced by
phellogen derived from phloem parenchyma) appear slightly
rectangular or square to isodiametric in TS and TLS and
4-6 sided in TLS.
The
rst 3-S layers of cells closest to
the phellogen are all thin-walled and filled with tannin.
18
Later some of the cells sclerify and grow to a few times
their original size, with 1
5G) while others only un de
the cells remain rat
Some
distinct lumina (Fig. 3C,
expansion.
isodiametric in all three planes.
n their tannin contents.
Crysta
commonly in the cell wall, especially
near the phellogen.
crystals
lent
« 8
~m
In both cases
occur
those of cells
There is very high accumulation of
long) between phelloderm cells under
Is (Fig. 5B,D,F,G) mostly hexagonal prismatic in
shape.
Lysigenous-type resin canals are plentiful in the
phelloderm (Fig. 6B), occurring just adjacent to the phloem
in one or two rows.
They have a diameter of about 50-70
~m,
and anastomose freely within each row (in the tangential
plane) .
The phellem cells produced by phellogen derived from
cortical cells appear narrowly rectangular in TS and TLS
(Fig. 4E,G)
(with long axes in
tangential horizontal
direction) and rectangular in RLS (Fig. 4A).
Those produced
by phellogen derived from phloem parenchyma appear narrowly
rectangular in TS and RLS and irregularly polygonal in TLS
(Fig. 4F).
In both cases, the walls are
though somet
ally thin,
they may vary in thickness, the outer
cells exhibiting slightly thinner walls (Fig. 4H).
The
tangential wall is usually thicker than the transverse and
radial wall, and the inner tangential wall may be slightly
thicker than the outer tangential wall (Fig. 5A).
stems,
outer 1
layers of
llem are thick-walled,
appearing rectangular to square in TS (F
4 6 sided in TLS and are larger in
the
layers.
. 4C) and RLS and
ze than the cells of
walls of such thick
seem slightly lignified and
In older
refringent.
led phellem
Phellem cells are
19
mostly without contents but some are filled with tannin,
the latter appearing In short tangential rows.
complementary t
sue of lenticels has high accumulation
of minute crystals
«
cell walls (Fig. 5G)
shape.
I
8
~m
long) occurring between the
mostly hexagonal prismatic in
A trabecula was observed
of the spec
The
(Fig. 5C).
the phellem of one
bark
Fig. 2
Agathis australis
A.-C.
General view of the inner part of the
living bark - TS(LM) x 60. The top of
Fig. 2A joins the bottom of Fig. 2Bi
the top of Fig. 2B joins the bottom of
Fig. 2Ci and the top of Fig. 2C joins
the bottom of Fig. 3A. This specimen
was broken off at the vascular cambium
(Vc) which is at
bottom of Fig. 2Ai
sclereids with large empty lumina (Sc) i
resin canals (Rc) i
rays (R-R').
Unlabelled arrow in Fig. 2A indicates
approximately the extent of the
conducting phloem;
sclereids
in
to appear slightly beyond the arrow!
to the outside, eventually
coming
very abundant.
bark
Fig. 3
Agathis australis
A.
Continuation of Fig. 2C, general view
of the living bark of the inner
TS(LM) x 60. The top of Fig. 2C joins
Fig. 3A.
the bottom
B.-C.
General view of the outer part of the
living bark - TS(LM) x 60. The top of
Fig. 3B joins the bottom of Fig. 3Cj
sclereids with large empty lumina (Sc);
resin canals (Rc) i
rays (R-R') i
phellem (Pm); phelloderm (Pd); expanded
phloem parenchyma cells (E). The ray
(R-R') in
. 3C has dil
The
primary cortex is absent in this
specimen. Note the phelloderm sclereid
with large distinct lumina in Fig. 3Ci
phloem sclereids are very abundant.
· 4
Agathis australis
bark
A.
Part of the periderm where the
is derived from cortical cells
x 1 080i note the rectangular
the phellem cells (Pm) and the
shape of the phelloderm cells
thin walls; phellogen (Pn).
phel
- RLS(SEM)
shape of
isodi
( ) with
B.
Thickened phelloderm cells,
phellogen derived from corti
RLS(SEM) x 1 080; note the i
shape.
c.
The outermost two layers of phel
cells
exhibiting thick walls (Th) , and appearing
rectangular in shape - TS(LM) x 625; thinwalled phellem cells (T).
D.
Thickened phelloderm cells, showing nonpolylamellate walls -RLS(SEM) x 2 700;
note the isodiametric
E.
Part of the periderm
the phellogen is
cells - TS(LM) x 310;
derived from cortic
note the narrowly
ar shape of the
cells; phellem (Pm); phelloderm (Pd).
F.
Phellem cells produced by a phellogen
derived from phloem parenchyma cells TLS(LM) x 310; note the irregular
polygonal
G.
Phellem cells
derived from
x 540; note
H.
Phellem
Is produced by a phellogen
derived from phloem parenchyma cells TS(SEM) x 540; note that the wall of
these thin-wal
phellem cells vary
slightly in thickness, those to the left
of the micrograph being thicker-walled
than those to the right. Arrow points
to the outs
of the stem.
by a phellogen
cells - TLS(SEM)
narrowly rectangular shape.
bark
Fig. 5
Agathis australis
A.
Wall of thin-wal
phellem cells TS(SEM) x 3 000; note that the inner
tangential wall (I) is slightly thi
than the outer wall (0), and that the
tangential wall is thicker than the
radial wall.
Unl
lled arrow points
to outside of the stem.
B.
Crystals (arrowed) between phelloderm
cells under lent
Is - RLS(SEM) x 1 030.
C.
Trabecula (arrowed) in phellem cells
from one tangential wall to the next TS(SEM) x 1 200.
D.
Enlarged micrograph of part of Fig. 2B
showing crystals between the phelloderm
cells - RLS(SEM) x 2 625.
E.
Thick-walled phelloderm cells produced
by a phellogen derived from cortical
Is - RLS{SEM) x 625;
note the
phelloderm cell (arrowed) developing
a sclerified wall, and also the
i
ametric shape of
cells.
F.
Cry
s (arrowed) adhe ng to the
outside of the wall of phelloderm cells
under a lenticel, when
cells were
pull
apart during cutting - TLS(SEM)
x 540.
G.
A lenticel under polariz
light,
showing the birefringent crystals in
the phelloderm (Pd) and
complementary
tissue (Ct)
TS(LM) x 50j phelloderm
s
(Sc);
phellem (Pm);
phellogen (Pn).
H.
(LM) x 60;
phelloderm
note the
ids lar shape.
Fig. 6
this australis
bark
A.
Early stage of the development of a
resin canal (arrowed) in the phelloderm
produced by a phellogen derived
cortical cells, prior to lysis of
central cells - RLS(LM) x 310; note
the thin-walled phelloderm cells (T)
with tannin contents near the phellogen
(Pn) and the thick-walled ones (Th)
away from the phellogen.
B.
Mature resin
(Rc) in the phelloderm
produced by a phellogen derived
axial parenchyma cells - TS(LM) x 160;
sclerified phelloderm cells with large
lumina (Sc).
C.
Cortical sc
and a nonerified
cortical cell (NSc) - RLS(SEM) x 1 050;
note the polylamellate walls (arrowed)
and the large
stinct lumina of the
sclereids.
D.
General arrangement of the ph
cells near
vascular cambium TS(LM) x 160; ray (R-R');
s
cells (S) i
ordinary axial parenchyma
with dark contents; axial parenchyma
with walls laid in the radial longitudinal
plane (unl
lIed arrows).
Note that
the cell
are scattered among each
other, and the rectangular to round
shape of f
(F) .
E.
Crystals ~arowed)
in axi
parenchyma
RLS(LM) x 310; note the hexagonal
prismat
shape.
F.
Dividing axial parenchyma mother cells
near the vascular cambium - TLg(SEM)
x 320;
radial longitudinal walls that
divide the mother cells into two strands
(unl
lIed arrows) i
sieve cells (S) i
rays (R) i note that
end wall is
laid down obliquely (Ob) and the round
shape of ray cells.
G.
A s
area - RLS(SEM) x 2 950. The
verti
diameter is ca. 13 ~m
and the
horizontal diameter is ca. 15 ~m.
Fig. 7
australis
bark
A.
s of fibre wall
TLS(SEM) x 3 120i
ray cells (R) adjacent to the fibre;
note the two thin lamellae on the
outside (1,2), followed by one thick
inner lamella (3).
B.
Fibres - TS(SEM) x 1 200; note the two
thin outer (1,2) and the thick inner (3)
lamellae;
sclereids (Sc).
C.
Phloem sclereids with large lumina
RLS(SEM) x 310.
area enclosed by
the box is shown under high power in
Fig. 7D;
fibre (F).
D.
A high power view of the area enclosed
in the box in F
. 7C, showing the wall
of the sclereids
RLS(SEM) x 3 000.
Cell I has a
layered wall; cell
II has three
rs and cell III has
two layers; middle lamella (arrowed).
E.
Phloem scI
s, showing a pit
(arrowed) - RLS(SEM) x 1 OlOi note
the large lumina and the polylamellate
wall; non s
ified parenchyma (NSc).
F.
A resin canal (Rc) in the phloem
TS(SEI'1) x 120.
G.
A developing resin canal (arrowed)
TS(LM) x 130; note the parenchyma
cells that have divided repeatedly
and the two
s (F) among
dividing parenchyma cells;
rays (R-R').
Fig . 7
bark
Fig. 8
Agathis australis
A.
A resin canal in the phloem ithelial cells
TLS(SEM) x 120;
(Ep) i parenchyma (P);
sclereid
with large lumen (Sc).
B.
Low power view of the phloem, showing
the distribution of resin canals in
tangential rows - TS(SEM) x 12;
the arrows show where the tangential
rows are.
Fig. 8
20
Libocedrus bidwillii Hook.
f.
were collected at breast height, the
Spec
diameters and living bark thicknesses being:
Diameter
(em)
Location of Trees
Living bark
thickness (mm)
(I) Inangahua West
State Forest
65.6
3.8
Inangahua West
State Forest
13.7
4.5
(3 ) Inangahua West
State Forest
18.0
3.0
(2 )
phloem consists of sieve cells, axial and ray
parenchyma and fibres, arranged in regular tangential rows
(Fig. 9A,B).
Every row of
al parenchyma eel
has a row of sieve cells on
parenchyma rows are
fibres
side.
always
These s
cell-
by 1-2, rarely 3, rows of
(Fig. llA).
The conducting phloem seems to be about
0.7-0.8 mm wide (Fig. 9A).
Sieve cells appear rectangular in TS, becoming
narrowly rectangular
the non-conducting phloem (Fig. llA).
are some minute crystals «
4
~m
long) in the radial
wall of sieve cells, but are sometimes absent in the nonconducting phloem.
The crystals are most
smatic in shape.
hexagonal
eve areas are about 6-9
~m
in
diameter (Fig. lIB), mostly on the radial walls in single
fi
Axial parenchyma cells are rectangular to isodiametric
in TS and rectangular in RLS and TLS.
with tannin.
They are mostly filled
Some minute crystals, most
prismatic in shape
«
4
~m
long)
hexagonal
to be located
radial wall of some parenchyma cells (Fig. lIe) but are
21
s absent in
somet
non-conducting phloem.
phloem rays are uniseriate, rarely part-bis
ate
(Fig. 110) and are 1 7 cells.high (up to 12 counted).
The cells appear rectangular in TS and RLS, and round to
elliptical (with long axes in the longitudinal direction)
in TLS (Fig. IlD,G).
Fibres are of two types, thin and thick-walled.
They are mostly thin-walled with 1
(Fig. 1
empty lumina
Thick-walled fibres have
,G).
and are scattered in the phloem, rare
row (Fig. 9A,B, 100, llA).
narrow lumina
forming a tangential
Both thin and thick-walled
fibres appear square to rectangular (with long axes in the
radial direction) in TS and elongated with pointed ends
in TLS
. IlG).
pointed
In RLS, some appear elongated with
However, most appear elongated with rather
blunt or abrupt ends like parenchyma cells
(Fig. 12A).
Thin-walled fibres have numerous slit pits (Fig. llE).
The walls
both thin and thick-walled
birefringent and seem to be
In thin-wal
are ligni
ed,
up of two main lamellae.
fibres, the wall consists of one very thin
lamella on the outside and one thin lamella on the inside
g. llE), whi
in thick-wal
one thin lamella on the outside
ide (Fig. 1
).
one thick
Some minute crystals
mostly hexagonal prismatic in
radial wall (in
fibres, it consists of
«
4
~m
lla on the
long) ,
are found in the
region of the middle lamella) of
s.
In all specimens studied, trabeculae were extremely
common, all traversing in the radial direction from one
tangential wall to the next (Fig. 12B,C,D).
22
The periderm consists of 2 3 layers of phellem,
one layer of phellogen and 2-3 layers of phelloderm
(Fig. lOA).
rectangu
Phelloderm cells are oblong in TS and
to oblong in RLS (Fig. lOA).
In TLS, those
phelloderm cells that are cut off by phellogen derived
from axial parenchyma cells are rectangu
whi
to six-sided
those cut off by phellogen cells derived from ray
parenchyma cells appear rather isodiametric and smaller
than those from axial parenchyma-derived phelloderm cells
(Fig. lOC,E).
The shape of the innermost phelloderm cells
resemble that of the original axial parenchyma cells from
which the phellogen is derived (Fig. lOA).
cells have thin walls;
phellogen cells.
Phelloderm
some contain tannin, as do some
Phellem cells are rectangular In TS
and RLS (Fig. lOA,B).
In TLS, those phellem cells that
are cut off by phellogen cells
ived from axial parenchyma
cells are 4-6 sided and are without contents.
Those cut
off by phellogen cells derived from ray parenchyma cells
are isodiametric and smaller in size, often having some
tannin contents.
Phellem cells are thin-walled, the walls
appearing rather flimsy (Fig. lOB).
Dead periderms and phloem are not exfoliated readily
.
,
but are accumulated as many sheets on the stem.
and s
Fibres
cells remain intact but parenchyma and phelloderm
cells collapse markedly in the radial direction (Fig. lOD,F).
Fig. 9
Libocedrus bidwillii
A.-B.
view of the living bark TS(LM) x 60. The top of
. 9A joins
the bottom of Fig. 9B. This specimen
was broken off at the vascular cambium
(Vc) which is at the bottom of
Fig. 9A;
rays (R-R') i
tangential
rows of axial parenchyma (P) i
thinwalled fibres (F);
scattered thick1
fibres (ThF); periderm (Pe) i
idome (Rh). The unlabelled arrow
in Fig. 9B indicates thick-walled
f
s in two tangent
rows which
is not a cornmon
The
unlabelled arrow in F . 9A indicates
approximately the extent of the
conducting phloem.
bark
Fig. 9
Fig. 10
Libocedrus bidwillii
bark
A.
Periderm - RLS(~1)
x 625; phellem (Pm);
phellogen (Pn) i
phelloderm (Pd). The
shape of innermost phelloderm cell
resembles the normal axial parenchyma
1 from which the phellogen cell
was derived;
the small white arrows
show the end walls of the innermost
phelloderm cell.
Subsequently, the
pnellogen cell divided in half, giving
se to the phelloderm cells that are
half the innermost onei
the big black
arrow indicates
cell wall that
divided the cell in half.
The two
phellogen cells then divided again,
giving
se to four
ls, each
one-quarter the length of the original
parenchyma cell;
small black
arrows indicate the
1 walls
associated with this last division.
Note
so the rectangular shape of
the cells.
B.
Phellem cells - TS(SEM) x 1 180;
note
thin flimsy walls and also
the rectangular shape.
c.
Phel
cells - TLS(LM) x 310;
arrows indicate those cells produced
by phellogen cells derived from ray
parenchyma cells;
all other cells
are products of phellogen cells
derived
axial parenchyma cells.
D.
Rhytidome
TS(LM) x 130; dead
periderm (Pe) i
thin-wal
fibres
(F) i
scattered thick-wal
fibres
(ThF) ;
sieve cells (S);
rays (R-R') i
note all axi
parenchyma cells (p) have collapsed.
E.
Phelloderm cells - TLS(LM) x 310;
arrows indicate those cel
produced
by phellogen
ls derived from ray
parenchyma
lSi
all other cells
are products of phellogen
ls
derived from
al parenchyma cells.
F.
Dead periderm - TS(LM) x 485;
phellem (Pm) i
collapsed dead
phelloderm ( ); dead s
cells
(S) i
collap
dead axial parenchyma
(P) i
thin-wal
fibre (F);
thickwalled fibre (ThF).
Fig. 10
Fig. 11
Libocedrus bidwillii bark
A.
Non-conducting phloem showing the
general arrangement of ce
- TS(LM)
x 310;
tangential rows of parenchyma
cells (P) with a row of
cells
(S) on each side;
eve cellparenchyma rows are
by 1-2
fibresi
thin-walled
(F) with
large lumina:
s
thick-walled
fibres (ThF).
B.
Sieve areas - RLS(SEM) x 3 000. The
top sieve area has a vert
diameter
of ca. 9 ~m
and a horizontal
ameter
of ca. 7 ~mi
the bottom one has
vertical and horizontal
s of
ca. 8 and 6 ~m
respectively.
C.
Crystals (arrowed) in the
1 wall,
exposed when the walls were pu
during preparation - RLS(SEM)
x 1 050.
D.
A part-biseriate ray (arrowed) TLS(LM) x 310: axial parenchyma
(p);
sieve cells (S);
a uniser
ray of 3-cell height (R), to the
of the micrograph. Note
ly elliptical shape of the
ray cells.
E.
Wall of thin-walled fibre
RLS(SEM)
x 2 750;
note one very thin lamella
on
outside (1) and one thin
lla on the inside (2); wall of
adjacent fibre (W) i
slit pits
(un
lIed arrows).
F.
Wa
of thick-walled fibre - TS(SEf1)
x 1 050; one thin lamella on the
(1) and one thick lamella on
(2); wall of adjacent
fibre (W).
Unlabelled
the position of the
lla.
G.
A TLS
of the phloem - TLS(LM)
x 160;
rays (R) i
thin-walled
fibres (F) with large empty lumina:
thick-wal
fibres (ThF). Note
the slight
elliptical shape of the
ray cells and the pointed ends of the
fibres.
Fig. 12
Libocedrus bidwillii
A.
Two macerated thin-walled fibres,
showing abrupt ends (arrowed) (Lf.1) x 310.
B.
An area of the phloem, showing
abundant trabeculae (arrowed) RLS(LM) x 160; thin-walled
fibres (F); axial parenchyma
bark
(P) •
c.
A trabecula (arrowed) traversing
fibres (F), s
cells (S)
and parenchyma (P) - TS(SEM}
x 575.
D.
A trabecula (arrowed) traversing
a sieve cell (S) and a thinwalled fibre (F)
TS(SEM} x 2 750.
23
Libocedrus plumosa
(Don) Sargent
Specimens were collected at breast height. the
diameters and living bark thicknesses being:
Diameter
(cm)
Location of trees
Living bark
thickness (mm)
( 1)
Omahuta State Forest
33.4
3.8
(2 )
Omahuta State Forest
41.5
4.6
(3 )
Omahuta State Forest
39.5
3.8
The phloem comprises sieve cells, axial and ray
parenchyma and fibres, arranged in regular tangential rows.
Every row of axial parenchyma cells always has a row of
sieve cells on each side.
These sieve cell-parenchyma rows
(Fig. l3A,B, l5A).
are usually separated by a row of fibres.
The conducting phloem is about 1.6-2.0
ITID
wide (Fig. l3A).
Sieve cells appear rectangular in TS
(Fig. l5A) with
little change in the non-conducting phloem.
crystals, hexagonal prismatic in shape «
Some minute
4 wm long)
are
found in the radial wall of sieve cells in the conducting
phloem.
Sieve areas are about 8-14 wm in diameter (Fig. l5B)
mostly on the radial wall in single file.
Axial parenchyma cells are rectangular to isodiametric
in TS, and rectangular in TLS and RLS.
filled with tannin.
prismatic in shape «
They are mostly
Abundant minute crystals, hexagonal
4 wm long) are located in the radial
wall of parenchyma cells in the conducting phloem.
phloem rays are uniseriate, rarely part-biseriate
(Fig. 160) and are 1-9 cells (up to 12 counted) in height.
The cells are rectangular in TS and RLS, but sometimes
24
appear constricted
TS at the point where a ray crosses
a tangential row of fibres (Fig. l5A)
in TLS, round
i
(Fig. l6D) to elliptical (with long axes in the longitudinal
direction), the latter shape especially at the areas where
a ray crosses a tangential row of fibres.
Fibres are of two types, thin and thick-wal
(Fig. l5A).
Both types appear square to rectangular
(with long axes
the radial direction) in TS (Fig. 1
and elongated with pointed ends in TLS.
In RLS, some
fibres appear elongated with pointed ends (Fig. l6B)
most, however appear elongated with rather blunt or
abrupt ends (Fig. l6C,E), like parenchyma
ls.
Thin-
walled fibres have large empty lumina and numerous slit
pits (F
. l5E).
Most thick-walled fibres have very
narrow lumina and lesser numbers of pits than thin-walled
fibres, leading to blind pits between thick and thin-walled
fibres
(F
(Fig. l5C).
(Fig. 16A).
l5D).
However, some are properly connected
Some thick-walled fibres possess large lumina
Minute crystals
occur in the wall
«
4 wm long) sometimes
al wall of fibres, in the region of
the middle lamella (Fig. l5F,G).
The
rm consists of 2 3 layers of phel
, one
layer of phellogen and 2-3, occasionally 4 layers of
phelloderm (Fig. l4A).
Phelloderm
ls are thin-walled,
rectangular to isodiametric in TS and RLS.
phelloderm cells produced by phellogen
In TLS, those
ls derived from
axial parenchyma cells appear 4-6 sided in shape while
those from ray parenchyma cells appear rather isodiametric
and smal
(Fig. l4B,D).
The shape of the innermost
phelloderm cells resembles that of the original axial
25
parenchyma from which the phellogen is derived, and are
invariably filled with tannin.
Some of the other
phelloderm cells are filled with tannin as are some
phellogen cells.
Phellem cells have thin flimsy walls
and are rectangular in TS and RLS
(Fig. 14A,C).
In TLS,
those phellem cells produced by phellogen cells derived
from axial parenchyma cells are 4-6 sided and without
contents, while those from ray parenchyma cells are
isodiametric, smaller (Fig. 14B) and often with some
tannin contents.
Dead periderms and phloem are not readily exfoliated
but are accumulated as sheets on the stem.
Fibres and
sieve cells remain intact but most parenchyma cells
collapse in the radial direction
(Fig. 14E).
Some appear
to possess lignified thickened walls made up of several
thin lamellae, in which case the cells remain intact
(Fig. l4E).
Dead phelloderm cells are sclerified with
polylamellate (Fig. 14F,G), lignified walls.
It therefore
seems that just prior to death, the phelloderm cells and
some of the axial parenchyma cells undergo changes in
wall structure.
bark
Fig. 13
Libocedrus
A.-B.
General view of the living bark TS{LM) x 60. The top of Fig. l3A
joins
bottom of Fig. l3B. Note
the tangential rows of thin (F) and
thick-walled (ThF) fibres, and axial
parenchyma (P) with sieve cells on
side; rays (R-R'). This
spec
was broken at the vascular
cambium (Vc) to the insi
and
(Pe) to the outs
Un
lIed arrow in Fig. 1
indicates approximately the extent
of
conducting phloem.
umosa
Fig. 13
Fig. 14
Libocedrus plumosa
A.
Living periderm, showing 3 layers of
phellem (Pm) and phelloderm (Pd), and
one layer
phello
(Pn) - RLS (UI)
x 310. Note rectangular shape of
cells.
B.
Living periderm, produced by phellogen
derived from ray cells (arrowed) size
RLS(LM) x 160; note the smal
isodiametric shape of the cells;
thin-walled fibre (F) i
thick-walled
fibre (ThF) i
axial parenchyma (P) i
ray (R-R').
c.
Living
iderm, showing the thin
flimsy walls of the phellem (Pm) TS(SEM) x 550; note the rectangular
shape of the cells. Arrow points
to
outside of the stem.
D.
Phelloderm cells
?LS(LM) x 160;
note that those produced by phellogen
ived from axial parenchyma cells
are 4-6 sided in shape while those
from ray cells (arrowed) are
isodiametric in shape and smaller
in size.
E.
Dead phloem in the rhytidome TS(LM) x 310. Fibres, both thin
(F) and thick-walled (ThF) , and
sieve cells (S) remain intact;
most parenchyma
ls collapse in
the radial direction (p) while
some with thickened walls remain
intact (Y).
F.
Dead phelloderm cells, showing the
polylamellate walls (arrowed) RLS(SEM) x 1 050.
G.
Dead periderm, showing scleri
phelloderm cells (Sc) - TS(U1) x 50;
remnants of phellem cells can be
seen at the top (arrowed).
bark
Fig. 14
Fig. 15
Libocedrus plumosa
bark
A.
The living phloem, showing the regular
tangential rows of
Is
TS(LM)
x 160. Note the rectangular shape of
sieve cells (S), rectangular to
isodiametric shape of parenchyma cells
(p) and the square to
shape of fibres;
fibres of two types:
thin-walled fibres (F) and thick-walled
fibres (ThF) i
ray (R-R I) •
is
constricted (unlabelled arrow) at the
point it crosses a row of
B.
areas - RLS(SEM) x 1 750. The
sieve area has a
diameter
of ca. 12 ~m
and a horizontal
ameter
of ca. 14 ~m.
ly connected pit (arrowed)
a thin-walled (F) and
(ThF) fibre - TS(SEM) x 2 675.
C.
D.
Blind pits (arrowed) between a thinwal
(F) and a thick-walled (ThF)
TS(SEM) x 2 675.
E.
Slit P
in the wall of a thin-wal
(arrowed) - RLS(SEM) x 1 180;
sieve cell (S);
axial parenchyma cell
(P) •
F.
Crystals (unlabelled arrows) adher
al wall of a thin-walled
to
the walls have been
fibre, a
pulled
during sectioning RLS (SEM) x 3 250;
pits (Pt).
G.
Wall of a
-walled fibre, showing
llae: one thin lamella
on the outs
(1) and one very thin
lamella on the inside (2) - RLS(SEM)
x 3 250;
c
Is (X) in the radial
of the middle lamella;
wall, in the
wall of adjacent fibre (W).
H.
Two thick-wal
s, showing the
wall with two main lamellae: one thin
lamella on the outside (1) and one
thick lamella on
inside (2) TS(SEM) x 4 740i wall of adjacent
sieve cells (W).
F
A.
. B.
• 16
Libocedrus plumosa
bark
Thick-walled
bres with large lumina
(L) - T8(8EM) x 1 200;
axial parenchyma
(P);
sieve cells (8).
A macerated thin-walled fibre with a
pointed end (arrowed) - LM x 310.
c.
A macerated thick-walled fibre with a
blunt end (arrowed) ~ LM x 310.
D.
A part-bi
ray, four cells in
height (arrowed)
TL8(LM) x 310.
Note the round shape of ray cells;
axial parenchyma (P).
E.
A
led fibre with an
macerated thin
LM x 310.
abrupt end (arrowed)
C
D
Fi g . 16
26
Dacrydium kirkii F. Muell. ex ParI.
Specimens were collected at breast height.
The
diameter and living bark thicknesses are as follows:
Location of trees
Diameter
(em)
Living bark
thickness (mm)
(1)
Puketi State Forest
41.0
8.8
(2)
Puketi State Forest
39.0
8.2
(3 )
Puketi State Forest
38.4
9.2
The conducting phloem comprises ray parenchyma and
short or long tangent
1 rows, sometimes individual cells,
of axial parenchyma separated by about 2-5 rows of sieve
cells and fibres scattered at random among each other
(Fig. 17D).
Sc
reids start to develop at random in the
non-conducting phloem, their abundance increasing centrifugally (Fig. l7A.-D.).
The conducting phloem is about
0.9-1.2 mm wide (Fig. l7A).
Sieve cells are rectangular to almost square in TS
(F
l7D), becoming crushed or slightly collapsed due to
sclereid growth in the outer part of the phloem.
crystals (ca. 15-30
~m
Large
long), mostly hexagonal to octagonal
prismatic in shape are found in some sieve cells of some
t~es
(Fig. l8A).
in a single cell.
crystals at
crystals.
1.
Sometimes, several crystals are located
Sieve cells of some trees do not have
The walls of sieve cells are devoid of
Sieve areas are about 5-12
(Fig. 18B), most
on the
~m
in diameter
al wall in single fi
Axial parenchyma cells are round in TS, rectangular
in RLS and TLS, some expanding towards the outside appearing
isodiametric in TS, RLS and TLS.
with tannin.
They are mostly
lled
Near the vascular cambium, the axial parenchyma
27
mother cell divides into strands.
Sometimes
transverse
wall is laid closer to each other than normal, such that
the cells appear almost square in TLS and RLS.
Sometimes
a radial wall is also laid down within such divided cells
(Fig. 18C).
down.
In other instances, an oblique wall is laid
Some parenchyma cells develop into sclereids
(Fig. 18D), growing irregularly to a few or many t
the
original size, elongated or isodiametric in shape with many
branches.
In the outer phloem, some of the non-sc
ified
parenchyma cells expand (and sometimes divide) becoming
rather isodiametric in all planes (Fig. 18E, 19E,F).
hexagonal to octagonal prismatic crystals (ca. 15 30
Large
~m
long)
are found ln some axial parenchyma cells in some trees.
Phloem rays are uniseriate, occasionally partbiseriate and about 1-18 cells high (up to 28 counted).
The
cells appear rectangular in TS and RLS and round in TLS
(Fig. 18C), becoming oval (with long axes in the horizontal
tangential direction) towards the outer part of the phloem
upon dilation (Fig. 18E).
Some ray cells develop into
sclereids, growing to many times the original size, tending
to have an elongat
shape.
Fibres are rectangular (with long axes in the
tangential direction) to square in TS (Fig. 17D), having
elongated form with pointed ends.
The
walls are thick
with small to almost indistinct lumina.
lignified and bire
2 main lamellae:
wall is
, and seems to be made up of
one thin lamella on the outside and one
thick lamella on the inside (Fig. 18F).
Phloem sclerei
phloem from ray and
start to develop in
al parenchyma cells.
stributed randomly, abundant in number, most
non-conducting
are
with small
28
or indistinct lumina, having isodiametric to elongated
form with many branches (Fig. 18G) , oriented generally
in the longitudinal direction.
filled with tannin;
Some have large lumina
others empty_
Their walls are
polylamellate, lignified and birefringent.
The primary cortex seems to persist for a long time
on the stem.
In younger sterns, the phellogen is derived
from cortical cells (Fig. 17C).
In older stems, the primary
cortex is absent and the phellogen is derived from phloem
parenchyma cells (Fig. 19E,F).
Cortical cells are iso-
diametric to rectangular or oblong in TS and TLS and isodiametric In RLS.
Some are filled with tannin.
cortical cells undergo sclerification.
Some
Cortical sclereids
are distributed randomly, tending to be in tangential bands
as seen in TS.
Some grow irregularly (Fig. l8H) to a number
of times larger than the original cells, possessing almost
indistinct lumina.
However, most sclereids remain about
the same size and shape as the original cells, possessing
distinct lumina
lled with tannin (Fig. 17C).
The periderm consists of about 30-70 layers of
phellem, one layer
phelloderm.
phellogen and about 8-15 layers of
In younger sterns where the phellogen is derived
from cortical cells, the phelloderm cells are rectangular
(with long axes in the horizontal tangential direction)
(Fig. 19A), becoming narrowly rectangular away from the
phellogen in TS and TLS, and round to slightly rectangular
in RLS. In
0
r stems where the phellogen is derived from
phloem parenchyma cells, they are rectangular to square in TS
and RLS and 4-6 sided in TLS (Fig. 19B).
phelloderm cells are ini
ly thin-wal
Both types of
and have tannin
29
contents (Fig. 19A) , as do phellogen cells.
Some
phelloderm cells sclerify, more or less retaining the
shape and size of the original cells.
cells possess distinct lumina
Minute crystals, mostly hexagonal
8
~m
ed phelloderm
lIed with tannin (Fig. 19B).
Their walls are polylamellate, ligni
«
Scleri
and birefringent.
smatic in shape
long) are found in the wall of phelloderm cells
under lenticels.
In younger stems where the
llogen is derived from
cortical cells, the phellem cells appear narrowly rectangular
in TS, rectangular in RLS and rectangular (with long axes
in the horizontal tangential direction) to 6-sided in TLS
(Fig. 19C).
In older stems (where the phellogen is derived
from phloem parenchyma)
I
they appear narrowly rectangular
in TS and RLS and 4-6 sided in TLS.
Some phellem cells are
without tannin contents while others are filled with tannin.
Most phellem cells have thin walls but some cells have
substantially thicker inner tangential wall which is
scI
fied and birefringent.
Fig. 17
Dacrydium kirkii
bark
A.-C.
General view of the living bark - TS(LM)
x 60. The top
Fig. 17A joins the
bottom of Fig. 17B and the top of
Fig. 17B joins the bottom of Fig. 17C.
This specimen was broken at the vas
ar
cambium (Vc) which is at the bottom of
Fig. 17Ai
rows of axial parenchyma (P) i
sclereids (Sc);
rays (R-R') i
primary
cortex (pc) i
phelloderm (pd);
phellem
(pm) i note some phloem sclereids in
Fig. 17B and most cortical cells in
Fig. 17C are filled with tannin;
phloem sclereids are abundant;
some
phellem cells with tannin contents
(unlabelled arrows) in Fig. 17C. The
specimen shattered during sectioning
(Fig. 17A). The unlabelled arrow in
Fig. 17A indicates approximately the
extent of the conducting phloem.
D.
General arrangement
phloem cells
near the vascular cambium - TS(LM)
x 310; short or long tangential rows
(sometimes individual c ls) of axial
parenchyma cells (p) f
separated by
about 2 5 rows of sieve cells (s) and
fibres (F) scattered among each other;
ray (r-r l ) . Note the rectangular to
isodiametric shape of parenchyma cells
and the rectangular-shaped fibres.
Fig. 18
Dacrydium kirkii
bark
A.
Hexagonal to octagonal prismatic crystals
(arrowed)
some sieve cells (s) RLS(LM} x 310; fibre (f) i
1
parenchyma (p). Crystal, labelled x is
polygonal prismatic in shape.
B.
A sieve area - RLS(SEM) x 2 375. The
vertical and horizontal diameters are
both ca. 10 ~m.
C.
A section near the vascular cambium
showing a parenchyma strand with transverse
walls laid closer to each other than
normal (pi) - TLS(LM) x 310; note also
the radial wall laid within one of the
cells (arrowed) i normal axial parenchyma
cells (p);
rays of height 9 cells (r)
and 4 cells (r');
ray
Is appear
round in shape.
D.
An axial parenchyma cell that is developing
into a scleried (arrowed) - RLS(LM} x 310;
non-sclerified axial parenchyma cells (p).
E.
A section in the outer part of the living
phloem, showing expanded
1 parenchyma
cells that appear rather isodiametric in
shape (pi) and some dilated
(r') sclereids (Sc);
unexpanded
TLS(LM} x 60;
axial parenchyma (p).
F.
Part of a fibre (f), showing the two main
lamellae of the wa
one thin lamella
on the outside (1) and one thick lamella
on the ins
(2) - TS(SEM) x 2 625; wall
of
acent sieve cell (W). This fibre
was immediately adjacent to the vascular
cambium, hence
a rather large lumen.
G.
Macerated phloem sclereids, showing
isodiametric to elongated shapes with
many branches (arrowed) - (LM) x 60.
H.
Macerated corti
sclereids, showing
their
ular shape -(LM) x 60.
Fig. 19
Dacrydium kirkii
A.
Phelloderm cells produced by phellogen
derived from cortical cells, showing
their rectangular shape - TS(LM) x 310.
Note the tannin contents.
B.
Phelloderm cells produced by phellogen
derived from phloem parenchyma, showing
the 4-6 sided shape - TLS(LM) x 310;
most of the cells are sclerified (Sc),
but retain the 4-6 sided shape;
unsclerified cells (U); note the
tannin contents.
c.
Phellem cells produced by phellogen
derived from cortical cells, showing
the rectangular to 6-sided shapes
- TLS(LM) x 310.
D.
Phellem cells - RLS(SEM) x 2 625;
cells to the left are thin-walled (T);
the rest have thick sclerified inner
tangential wall (I). Small unlabelled
arrows indicate where the middle
lamella is. Large unlabelled arrow
at bottom right points to the outside
of the stem.
E.-F.
General view of the outer part of the
living bark - TS(LM) x 60;
sclereids
(Sc);
expanded parenchyma (e) with
their isodiametric shapes; phelloderm
(pd); phellem (pm);
rays (r-r').
This specimen lacks primary cortex;
the phellogen is derived from phloem
parenchyma.
bark
Fig. 19
30
Dacrydium biforme
(Hook.) Pilger
Specimens were col
at breast height.
The
and living bark thicknesses of the s
as
1
Diameter
Location of trees
Living bark
thickness (rnrn)
( ern)
(1) Inangahua vJest
State Forest
13.0
5.5
(2 ) Inangahua West
State ,Forest
22.3
8.4
Inangahua West
State Forest
21.5
6.2
(3 )
are
The conducting phloem consists of long, sometimes
short, tangential rows of parenchyma cells separated by
about 2-5 rows
sieve cells
random (Fig. 20A,C).
ed with fibres at
Scattered sc
ids are found in
outer part, occasionally in the inner part of the nonconducting phloem (Fig. 20A,B).
conducting phloem
about 1.0-1.2 rnrn wide (Fig. 20A).
Sieve cells are rectangular to square in TS
Many large hexagonal prismatic crystals
~m
(10-60
(Fig. 20C).
long) occur
in some sieve cells, frequently filling a whole cell.
the outer part
the non-conducting ph
In
, the number of
crystals is less than that in the inner phloem.
In the non-
conducting phloem,
cells collapse un
crystals in the lumina.
Their walls do not include any
crystals.
Sieve areas are about 5-9
on radial walls in single file
~m
s they have
diameter, mostly
(Fig. 20E)
Axial parenchyma cells are isodiametr
and rectangular in TLS and RLS, mostly fill
Some of them contain
in TS
(Fig. 20C)
with tannin.
Is, mostly hexagonal prismatic
31
(10-60
~m
long), but appearing as minute styloid crystals
near the vascular cambium (Fig. 21A). When the parenchyma
mother cells divide, sometimes a wall is laid down in the
radial longitudinal plane.
The transverse wall is sometimes
laid obliquely in a similar fashion as in the phloem axial
parenchyma of
this australis.
Some axial parenchyma cells
develop into sclereids (Fig. 20B) growing to a few times
the original size with a rather elongated shape.
Most axial
parenchyma cells expand towards the phelloderm, becoming
rather isodiametric in all planes (Fig. 21C,F).
phloem rays are uniseriate, occasionally partbiseriate and about 1-20 cells high, sometimes more (up to
36 counted).
The cells appear rectangular in TS and RLS,
sometimes tending to be rhombic in RLS (Fig. 21C) and round
in TLS (Fig. 21B), eventually becoming oval towards the
phelloderm.
A few ray cells become sclereids, growing only
to a few times larger than the original cells (Fig. 21D).
Fibres are rectangular to narrowly rectangular in
TS
(with long axes in the tangential direction) (Fig. 20C),
having elongated form with pointed ends.
Their walls are
thick, lignified and birefringent, with two main lamellae:
one very thin lamella on the outside and one thick lamella
on the inside (Fig. 2lE).
The lumina are very narrow.
Phloem sclereids are developed from some axial
parenchyma and a few ray parenchyma cells.
Most sclereids
develop in the outer part of the non-conducting phloem but
a few develop in the inner part.
The sclereids generally
have an elongated shape, oriented in the longitudinal
direction, with a size that is only a few times larger than
the original parenchyma cells.
random (Fig. 20A,B, 2
They are distributed at
), sparse in number (Fig. 20A, B),
32
mo
without distinct lumina but some with small lumina
lIed with tannin.
Their walls are polylamellate, bire-
ingent and lignified.
The primary cortex seems to pers
on the stem.
t
for a long time
Cortical cells are isodi
(with long axes in the tangent
1
to rectangular
zontal direction) in
TS (Fig. 2lG) and TLS and isodiametric
tannin contents.
Some develop into s
RLS, mostly with
reids, growing only
to a few times larger than the original cells, rather isodiametric in shape with many branches (Fig. 21A), mostly without large lumina.
A few of
have distinct lumina filled
with tannin.
In younger stems
phellogen is derived from
cortical cells, the phellem is about 25-40 layers thick while
In older stems where the
it is about 15-25 1
lS
is from phloem parenchyma,
s
one layer and phel
In both stems, the phellogen
rm about 10-15 layers.
Phelloderm cells in younger stems are initially
to isodiametric in TS and 4-6 sided in TLS, eventually
becoming narrowly rectangular in both planes (with
in the tangential horizontal direction).
to be square-
axes
In RLS,
tend
initially, becoming isodiametric.
Those
in older stems are square to rectangular in TS and RLS
(Fig. 22A) and 4-6 sided in TLS (Fig. 22B).
the walls
the cells
In both stems,
phelloderm cells are initially thin.
tannin contents (Fig. 20B, 22A,B) as do
phellogen cells. Some phelloderm cells develop sc
walls but do not expand extensively, the walls
lamel
Most of
refringent and lignified.
Such sc
fied
ing polyfied
phelloderm cells retain their tannin contents (Fig. 22A).
Small and minute hexagonal prismatic crystals (mostly <
10
~m
some up to 25
~m
long) are p
iful in the
33
walls of phelloderm cells in the region of the middle
lamella, under lentic
s
(
. 22C) but are absent elsewhere.
In younger stems, phellem cells appear narrowly
rectangular in TS and RLS and 4-6 sided in TLS, tending to
be elongated, having long axes in the tangential horizontal
direction, mostly with tannin contents, and thin-walled
(Fig. 22G).
In older stems,
are rectangular in TS and
RLS, and 4-6 sided in TLS, having thin walls (Fig. 22D,E).
Some however have a thicker s
inner tangential wall (Fig. 22E,F).
possess tannin contents (Fig. 20B).
and birefringent
Most phellem cells
Fig. 20
Dacrydium biforme
A.-B.
General view of the living bark - TS(LM)
x 60.
The top of Fig. 20A joins
bottom of Fig. 20B. This specimen was
broken off at the vascular cambium (Vc),
at the bottom of Fig. 20A;
rows of
axial parenchyma (p); sclereids (Sc)
sparse in number; rays (r-r') i
expanded parenchyma (e)i phelloderm
(pd) i
phellem (pm). The phelloderm
cells, phellem cells and axial parenchyma
Is are mostly tannin- lIed.
The
unlabelled arrow in Fig. 20A indicates
approximately the extent of the
conducting phloem. The primary cortex
is absent in this specimen.
C.
General arrangement of phloem cells
near the vascular cambium - TS(LH) x 310;
tangential rows of axial parenchyma
cells (p) separated by about 2-5 (5 in
this micrograph) rows of sieve cells (s)
interspersed with fibres (f) at random;
rays (r-r l ) . Note the rectangular to
square shape of sieve cells, the
isodiametric shape ofaxi
parenchyma
cells and the rectangular to narrowly
rectangular shape of fibres.
D.
Crystals (x) in sieve
Is (s) in the
non-conducting phloem - TS(LM) x 625;
axial parenchyma cells (p);
fibres
(f);
ray (r-r l ) .
E.
Two sieve areas in single fi
on the
radial wall
RLS(SEM) x 2 500.
The top sieve area has a verti
and
horizontal diameter of about 6 and 7 ~m
respectively, and the bottom sieve area
has a vertical and horizontal diameter
of about 8 and 8 ~m
respectively.
bark
Typical crystals (x) found in sieve and
axial parenchyma ce s - TLS (U1) x 310.
Fig. 20
bark
Fig. 21
Dacrydium biforme
A.
Styloid crystals (arrowed) in axial
parenchyma cells near the vascular
cambium - TLS(LM) x 625.
B.
An area showing a sclereid developing
from an axial parenchyma cell (Sc)
and rays (r) - TLS(LH) x 310;
axial
parenchyma cells (p); note the
round shape of ray cells.
c.
Expanded axial parenchyma cells (p)
near the phelloderm - RLS(Ll1) x 160;
rays (r-r') i
note their rather
isodiametric shape and also the
rectangular to slightly rhombic
shape of the ray cells.
D.
A scleri
ray cell (Sc)
a few
times larger than the original
1 - TS(Ll1) x 310i
axial
parenchyma (p) i expanded axial
parenchyma cell (E)i
sieve cells
(s);
crystals (x) i
ray (r-r I) •
E.
A fibre showing the two lamellae of
the wall: one very thin lamella on
the outside (1) and one thick lamella
on the inside (2)
TS(SEM) x 4 500;
wall of adjacent sieve cells (W).
F.
An area under partial polarized
light, showing randomly scattered
sclereids (Sc), expanded
al
parenchyma with dark tannin contents
TS(LM) x 60;
rays (r-r'). The
smal
birefringent spots are
crystals.
G.
The primary cortex (pc) showing the
isodiametric to rectangular shape of
the cells - TS(LM) x 60; phloem
(phl) •
H.
Macerated cortical sclereids -~M)x
note the many branches (arrowed).
I
160;
Fig. 22
Dacrydium biforme
A.
Phelloderm cells produced by a phellogen
derived from phloem
, showing
the square to rectangular shape of the
cells - RLS(LM) x 310.
cells are
all tannin-filled.
Some of the cells
(Sc) possess sclerifi
walls.
B.
Phelloderm cells produced by a phellogen
derived from phloem parenchyma, showing
the 4-6 sided shape of the cells
TLS(LM) x 310.
c.
Crystals (arrowed) in the wall (in the
region of the middle lamella) of
phelloderm cells, when cells are pulled
apart during preparation - RLS(SEM) x
1 000.
D.
Thin-walled phellem cells, showing
ir
wall with equal inner (I) and outer (0)
tangential wall thicknesses - TS(SEM) x
Unlabelled arrow at top
2 750.
points to outside of the stem.
E.
lem cells, showing both thin
cells (T) and also ones with thi
sc
ified inner tangential wall (I)
TS(LM) x 625.
F.
A phellem cell with a thicker sc
tangential wall (I) and a thin
non-sclerified outer wall (0) TS(SEM) x 2 750; middle lamella (ml).
To
right is a thin-walled phellem
cell (T) with a thin inner tangential
wall (i).
Unlabelled arrow at bottom
right po
to the outside of the stem.
G.
ls produced by a phellogen
Phellem
cortical cells, showing
derived
the
·4-6 sided shape, tending to be
the tangential horizontal
elongated
direction, with tannin contents and
thin wal
TLS (L.r.1) x 310
Fig . 22
34
um bidwillii
Hook. f. ex Kirk.
Specimens were collected at a point
the stern/root junction.
30 ern from
The diameters and living bark
thicknesses of the samples are as follows:
Location of plants
Diameter
(rnrn)
(I) Burnt Face,
Bealey State Forest
16.4
1.75
(2) Burnt Face,
Bealey State Forest
18.9
2.00
(3 ) Burnt Face,
Bealey State Forest
19.3
1. 75
The conducting phloem consists of sieve cells, axial
and ray parenchyma cells and f
regularity of pattern.
scattered without any
Sometimes, axial parenchyma cells are
in short tangential rows (Fig. 23B).
Scattered sclereids
occur in the non-conducting phloem (Fig. 23A).
~m
conducting phloem is about 110-125
Sieve cells appear
vascular cambium contain a
of 8-20
0
totally filled with crystals.
prismatic crystals «
4
of sieve cells,
~m
~m
long while others are
A few minute hexagonal
long) are found in the radial wall
of the middle lamella.
sieve cells without crys
neighbouring s
diameter (Fig. 23D)
wide (Fig. 23A).
ar in TS (Fig. 23B,G).
Some sieve cells away from
few crystals of the
The
in their lumina are crushed by
Sieve areas are about 4-9
f
Those
~m
in
mostly on the radial wall in single
file.
Axial parenchyma cells are round in TS (Fig. 23B,G)
and rect
TLS and RLS, with tannin contents.
parenchyma cells contain abundant crystals of 8-50
~m
Many
35
length (Fig. 23E), mostly of hexagonal
smatic shape.
Some form sclereids in the non-conducting phloem, growing
only a
times larger than their original size (Fig. 23G).
Phloem rays are uniseriate, rarely part-biseriate and
are 1 6 cells high (up to 10 counted).
They are rectangular
in TS and RLS and round to slightly elliptical (with long
axes in the axial direction) in TLS.
Fibres are narrowly rectangular to rectangular
TS
(~ith
long axes in the tangential direction)
having an elongated form with pointed ends.
thick, lignif
2 main lamellae:
(Fig. 23B,G),
Their walls are
and birefringent and seem to be made up of
one very thin lamella on the outside and
one thick lamella on the inside (Fig. 23F).
The lumina are
small to almost indistinct (Fig. 23F).
phloem sclereids are formed from axial parenchyma
cells, growing to only a few times the original size, having
an elongated shape (Fig. 23H) oriented in the longitudinal
direction, appearing mostly isodiametric in TS (Fig. 23G) ,
with almost indistinct lumina.
However, some sclereids
possess small empty lumina.
Sclereid walls are polylamellate,
ligni
phloem sclereids are moderate
and birefringent.
to abundant in number (Fig. 23A).
In all specimens examined, the primary cortex is
present.
Cortical cells are rectangular in TS and TLS (with
long axes in the tangential horizontal direction) and
isodiametric in RLS, tending to be isodiametric in all planes.
Some become sc
ze, the
fied, growing to a few times their original
shape tending to be isodiametric (Fig. 231).
Sclereids in the cortex tend to be in short tangential
bands or groups, a few
together (Fig. 24A).
Is in a local region scleri
ing
Some of the cortical sclereids have
36
indistinct lumina, while others have lumina (Fig. 24B)
filled with
The periderm comprises about 18-30 layers of phellem,
one layer phellogen and about 3-7 layers of phelloderm.
The phellogensin all specimens examined have
cortical cells.
sen from
and
Phelloderm cells are thin-wal
appear narrowly rectangular to rectangular in TS and TLS
and isodiametric in RLS
(F
. 24C), some being
lled with
tannin. Slightly thickened walls develop in some phelloderm
cells (Fig. 24C).
Minute crystals «
5
~m
long) are present
between phelloderm cells only under lenticels, in abundance,
mostly hexagonal prismatic in shape.
Phellogen cells are
invariably filled with tannin (Fig. 24D).
llem cells
are narrowly rectangular to rectangular in TS, mostly
rectangular to elongated polygonal with long axes in the
tangent
1 horizontal
have thin walls while
sc
rection (Fig. 24D) in TLS.
Some
s have a substantially thicker
fied inner tangantial wall (Fig. 24E) which is bire-
fringent.
(Fig. 24D).
Most phellem cells are filled with tannin
Fig. 23
Dacrydium bidwillii
A.
General view of the living bark - TS(LM)
x 60;
rays (r) i
scattered sc
ids
(Sc), moderate to abundant in number;
primary cortex (pc) i
phelloderm (pd) i
phellem (pm) i
xylem (Xy) i
vascular
cambium (Vc).
The unlabelled arrow
indicates approximately the extent of
the conducting phloem.
B.
General arrangement of the phloem cells
near the vascular cambium (Vc) - TS(SEM)
xylem (Xy) i
sieve cells (s);
x 1 100;
axial parenchyma cells (p) in short
tangential rOWSi
fibres (f).
Sieve
cells appear rectangular, axial parenchyma
cel
appear round and fibres appear
narrowly rectangular to rectangular.
Unlabelled arrow points to the outs
the stern.
c.
A sieve cell totally fil
with
crystals (arrowed) - RLS(LM) x 3l0i
axial parenchyma cells (p).
D.
A sieve area - RLS(SEM) x 5 250.
The
vertical and horizontal diameters are
ca. 8 and 7 ~m
respectively.
E.
Crystals (X) in an
al parenchyma
cell
TS(SEM) x 1 050;
sieve cells (s);
axial parenchyma cells (a).
F.
A fibre showing the two main lamellae of
the wall:
one very thin lamella on the
outside (1) and one thick lamella on the
inside (2)
TS(SEM) x 5 250;
wall of
adjacent sieve cells (W).
Note the
almost indistinct lumen.
G.
A sclereid (Sc) in the phloem appearing
isodiametric - TS(~1)
x 310;
axial
parenchyma (p);
s
cells (s) i
fibres (f).
Sieve cells appear
rectangular,
al parenchyma cells
appear round and fibres appear narrowly
rectangular to rectangular.
H.
Macerated phloem sclereids, showing their
elongated shape -(LM)x 60;
fibres (f).
1.
Macerated cortical sclereids, showing
rather isodiametr
shape -(LM)x 60.
bark
Fig . 23
Fig. 24
Dacrydium bidwillii bark
A.
An area of the primary cortex, under partial
polarized light, showing the sclereids (Sc)
in short tangential bands or groups TLS(LM) x 60.
B.
Cortical sclereids with large lumina (L)
- TS(SEM) x 525;
phloem axial parenchyma (p).
C.
Part of the periderm, showing some phelloderm
cells with slightly thickened walls (Th) RLS(LM) x 310;
phelloderm (pd);
tanninfilled phellogen (pn);
phellem (pm).
Note
the isodiametric shape of phelloderm cells.
D.
Phellem cells, showing
to elongated polygonal
axes in the tangential
- TLS(LM) x 310.
Note
E.
Phellem cells, showing some cells
thin walls (T) and two cells with
sclerified inner tangential wall
arrows) - TS(SEM) x 1 070;
outer
wall of adjacent thin-walled cell
their rectangular
shape (with long
horizontal direction)
the tannin contents.
with
thicker
(unlabelled
tangential
(0).
37
Hook. f.
Dacrydium laxifolium
Specimens were collected at a point about 30 cm
from the stem/root junction.
The diameters and living
bark thicknesses are:
Living bark
thickness (rom)
Location of plants
Diameter
(rom)
(1) Arthur's Pass
National park
3.5
0.61
(2) Arthur's Pass
National park
2.6
0.68
(3) Arthur's Pass
National park
2.5
0.34
ray parenchyma and tangential
The phloem consists
rows of axial parenchyma separated by 2-5 rows of sieve
cells.
Fibres seem to
present in some plants, usually
replacing some of the sieve cells at random. In barks
that possess fibres, sclereids are pre
, but rather rare.
The conducting phloem is very narrow, probably not exceeding
8-10 cells wide i.e. about 25
~m.
Sieve cells are narrowly rectangu
in
tangential direction)
(F
r
(with long axes
• 25B,C) with abundant
minute variously shaped prismatic crystals «
5
~m
long)
present in the wall, occurring in high concentration in the
radial walls
(F~g.
25D).
crystals (up to about 40
There are also abundant large
~m
in shape in the lumina of s
phloem (Fig. 25E).
the s
cells;
long) mostly hexagonal prismatic
cells in the non-conducting
Only the crystals mark the position of
otherwise they appear collapsed.
areas are about 3-5
~m
Sieve
in diameter, mostly on radial walls
in single file (Fig. 25F).
38
Axial parenchyma
ls appear isodiametric to
slightly elliptical in TS (Fig. 25B,C,D) and rectangular
in RLS and TLS, sometimes filled with tannin.
In plants
with phloem fibres, a few axial parenchyma cells sometimes
develop into sclereids, but remaining about the same shape
and size as the original cells or growing slightly,
becoming isodiametric.
prismatic crystals
«
axial parenchyma cells
Some minute variously-shaped
5
~m
long) occur in the wall of
(Fig. 25D).
Phloem rays are uniseriate, 1-7
ls high (up to
10 counted) and are round in TLS and oblong to isodiametric
in TS and RLS, sometimes appearing rather upright in RLS
(Fig. 26A).
There are minute various
shaped
smatic
crystals in the walls between ray and axial cells, with
high accumulations
the inter-cellular spaces between
ray and axial cells.
Fibres are only present in some plants.
They are
rectangular in TS (with long axes in the tangential
direction)
ends
(Fig. 25C), having elongated form with pointed
(Fig. 26B), possessing thick walls with
indistinct lumina (Fig. 26C).
1, almost
The wall seems to
birefringent and made up of 2 maln lamellae:
ligni
one thin
lamella on the outside and one thick lamella on the inside
(Fig. 26C).
crys
region
s
«
Some minute variously-shaped
5
~m
ismatic
long) occur in the wall of fibres, in the
the middle lamella.
Phloem sclereids seem to be present only in the phloem
of plants that possess phloem fibres.
The presence
at random, in the non-conducting phloem.
rare,
They are developed
from axial parenchyma cells, remaining about the same shape
39
and size of the original cell or growing slightly to an
isod
c shape.
lignifi
walls are po
and birefringent.
lamellate,
They have almost indistinct
lumina.
primary cortex
col
present in all the specimens
Cortical cells are isodiametric to slightly
oblong (with long axes in the horizontal tangential
direction) in TS and TLS and isodiametric in RLS.
crystals «
15
long;
~m
mostly < 4
Abundant
are located in the
~m)
wall, in the region of the middle lamella.
The periderm consists of about 5-11 layers phellem,
one
of phellogen and about 2 4 layers of
loderm.
Phelloderm cells are rectangular to oblong (with long axes
in the tangential horizontal direction) in TS and are
sometimes difficult to distinguish from cortical cells.
In RLS, phelloderm cells appear rectangular to isodiametric
and 4-6 sided to oblong or rectangular in TLS (Fig. 26D).
Their walls are thin.
with tannin.
Some phelloderm cells are filled
Some minute crys
s
«
8
~m
long), mostly
hexagonal prismatic in shape occur ln the wall
phelloderm cells.
of some
Phellem cells are rectangular in TS
and RLS, 4-6 sided (Fig. 26E) tending to be slightly
rectangular (F
. 26F) in TLS, mostly without contents.
Some phellem cells especial
the inner 2 3 layers have
thicker inner tangential
which is slightly birefringent
but not sc
ified (Fig. 26G,H).
Cone-shaped structures
protrude from the inner tangential wall into the lumen
(Fig. 26H).
trabecula-l
Other phel
cells have thin walls.
A
structure was observed in one specimen,
traversing from transverse wall to transverse wall through
40
a few phellem cells (Fig. 26G);
fungal hypha.
it could have been a
bark
Fig. 25
Dacrydium laxifolium
A.
General view of the living bark TS(LM) x 160; xylem (Xy); vascular
cambium (Vc);
primary cortex (pc);
periderm (pe).
The unlabelled arrow
indicates approximately the extent
of the conducting phloem.
B.
General arrangement of phloem cells
(a specimen without fibres)TS(SEM) x 1 020;
tangential rows of
axial parenchyma (a) separated by
2-5 rows of sieve cells (s).
Note
the narrowly rectangular shape of
sieve cells and the isodiametric to
slightly elliptical shape of axial
parenchyma cells. This specimen
was broken off at the vascular
cambium (Vc).
Unlabelled arrow
points to the outside of the stern.
c.
General arrangement of phloem cells
(a specimen with fibres) - TS(SEM)
fibres (f) i
tangential
x 525;
rows of axial parenchyma (a)
separated by 2-5 rows of sieve
cells (s).
Note the narrowly
rectangular shape of sieve cells,
the isodiametric to slightly
elliptical shape of axial parenchyma
cells and the rectangular shape of
fibres.
This specimen was broken
off at the vascular cambium (Vc).
Unlabelled arrow points to outside
of stern.
D.
Non-conducting phloem, showing
collapsed sieve cells indicated only
by crystals in their lumina (x) TS(LM) x 625. Note crystals in
the radial wall (arrowed) and the
isodiametric to elliptical shape of
axial parenchyma cells (a).
E.
Hexagonal prismatic crystals (X)
in the lumen of a sieve cell TLS(LM) x 625.
F.
Sieve areas in single file RLS(SEM) x 5 150. Both the
vertical and horizontal diameters
of the top sieve area are ca. 3.5 ~m
while the bottom sieve area has a
vertical diameter of ca. 5 ~m
and a
horizontal diameter of ca. 4 ~m.
Fig . 25
Fig. 26
Dacrydium laxifolium
A.
A ray of two-cell height (R-R ' ),
showing the rather upright ray
cells - RLS(SEM) x 525;
large
crystals (arrowed) from cell
lumina.
B.
A macerated fibre, showing the
elongated form with pointed ends
(arrowed) -(LH)x 60.
C.
Fibres, showing the two main
lamellae of the wall: one thin
lamella on the outs
(1) and
one thick lamella on
inside
(2)
TS(SEM) x 2 625;
sieve
cells (s) i
crystal (x) in the
wall, in the region of the
middle lamella.
Note that the
lumina is very small.
D.
loderm cells, showing their
oblong to rectangular
TLS(LM) x 310.
E.
4 6 sided phelloderm ce
TLS(LH) x 310.
F.
Phe
cells, showing the
tendency of being rectangular
in
- TLS(LM) x 310.
G.
Phellem cells, showing the thick
inner non sclerified wall
RLS(SEH)
x 2 550;
small unlabelled arrows
indicate where the middle lamella
is (though not clear in this
micrograph) i
outer tangential
wall (0) i
inner tangential wall
(I).
Note
trabecula-like
structure (t) traversing through
the transverse wall.
Large
unlabelled arrow points to the
outside of the stem.
H.
Cone-shaped structures (Co)
protruding into the lumen from the
inner tangential wall (I) which is
thicker than the outer tangential
wall (0) - RLS(SEM) x 5 250.
Unlabelled arrow indicates the
position of the middle lamella.
bark
s-
\"
ly...
.'.
. '-" .
•
41
Dacrydium cupressinum
Lamb
Specimens were collected at breast height,
diameters and living bark thickness being:
Diameter
(em)
Location of trees
(1)
Living bark
thickness (mm)
Ianthe State Forest
42.8
6.5
(2 ) Ianthe State Forest
67.8
6.5
Ianthe State Forest
60.0
7.6
34.0
7.6
42.5
5.0
(3 )
(4 ) Inangahua West
State Forest
(5)
Inangahua West
State Forest
The conducting phloem con
sts of ray parenchyma and
short tangential rows of axial parenchyma separated by 1-5
cells made up of sieve cells and fibres interspersed
with each other.
Sclereids begin to appear
the outer
of the conducting phloem at random, the number
increasing towards the phelloderm.
The width of the
conducting phloem is about 1.2 1.7 mm (Fig. 27A,B).
Sieve cells are square to rectangular in TS (Fig. 28A)
mostly crushed in the non-conducting phloem.
abundant minute crystals «
8
~m
Very
long), mostly hexagonal
smatic in shape occur in the radial walls of sieve cells
(Fig. 28B), throughout
6-15
~m
phloem. Sieve areas are about
in diameter (Fig. 28C), mostly on the radial wall
in single file
(Fig. 28B).
Axial parenchyma cells appear round to elliptical
in TS (Fig. 28A) and rectangular in RLS and TLS.
In the
immediate proximity of the vascular cambium, the parenchyma
mother cells divide 'abnormally', often forming walls in the
42
radial longitudinal plane and also in the transverse
plane, thus giving two strands of parenchyma adjacent to
each other, as in the case of Agathis australis
(Fig. 28D).
Sometimes the transverse wall is laid down obliquely, or
that the wall in the radial longitudinal plane is not
completely 'radial' but joins the radial wall of the
mother cell (Fig. 28D).
These give rise to abnormally-
shaped parenchyma in the initial stages.
Some parenchyma
mother cells do not seem to undergo transverse divisions
to form strands but remain as very long parenchyma cells
(Fig. 28E).
Some parenchyma cells are T or L-shaped as
seen in RLS, with part of the cell in rays
(Fig. 28F,G).
Axial parenchyma cells are mostly filled with tannin
contents (Fig. 28A).
The radial walls of some parenchyma
cells appear corrugated, the wall between pit fields
protruding into the lumina (Fig. 28B, 29A). Such parenchyma
cells are usually wider than the normal parenchyma cells.
Some become sclerified (Fig. 29C), growing irregularly to
many times the original size, tending to be elongated,
oriented in the longitudinal direction.
Later-formed
sclereids seem to be smaller and more isodiametric.
Non-
sclerified axial parenchyma cells expand slightly towards
the outside, as seen in TS
rectangular in RLS and TLS.
«
8
~m
(Fig. 29B) but remain rather
Abundant minute crystals
long), mostly hexagonal prismatic in shape, are
found in the radial wall of axial parenchyma cells, throughout the phloem (Fig. 29C).
Phloem rays are uniseriate, occasionally partbiseriate and 1-30 cells high (up to 50 counted).
are rectangular in TS
They
(Fig. 28A) and RLS and round in TLS
43
(Fig. 28D), becoming oval upon slight dilation in the
outer part of the non-conducting phloem.
Some ray cells
(especially those at margins) have tannin contents.
These
seem to be cells that are part of the Land T-shaped
axial parenchyma cells.
Some ray cells develop into
sclereids (Fig. 27A, 29C), growing to many times in size,
tending to be elongated ln shape, oriented in the longitudinal
direction.
However, a few are sclerified but do not expand.
There are very abundant minute hexagonal prismatic crystals
«
8
~m
long) in the inter-cellular spaces between ray and
longitudinal cells (Fig. 29D,E).
Fibres have an elongated form with pointed ends, mostly
narrowly rectangular in TS (with long axes in the tangential
direction) (Fig. 28A).
Their walls are thick and seems to
be made up of two main lamelle:
one thin lamella on the
outside and one thick lamella on the inside (Fig. 29F). They
are lignified and birefringent.
The lumina are almost
indistinct.
Phloem sclereids are developed from axial and ray
parenchyma cells.
They begin appearing in the outer part of
the conducting phloem, eventually becoming very abundant
(Fig. 27A,B).
Most sclereids grow irregularly to many
times the size of the original cells, tending to be slightly
elongated (Fig. 29G), oriented in the longitudinal direction,
sending branches, crushing some sieve cells and axial
parenchyma cells, growing into the space originally occupied
by them (Fig. 29H).
They are distributed randomly, mostly
with indistinct lumina (Fig. 27A,B).
A few have fairly
large empty lumina or ones filled with tannin.
are polylamellate, lignified and birefringent.
Their walls
43a
The periderm consists of about 30-70 layers of
phellem, one layer phellogen and about 13-17 layers of
phelloderm.
Phelloderm cells are isodiametric to
rectangular (with long axes mostly in the tangential
direction;
sometimes in the radial direction) in TS,
isodiametric to rectangular (with long axes mostly in the
longitudinal direction;
direction) in RLS
in TLS.
sometimes in the radial horizontal
(Fig. 30A) and 4-6 sided to isodiametric
The first few layers closest the phellogen are all
thin-walled and filled with tannin, as do phellogen cells.
Further away from the phellogen, a number of phelloderm
cells develop into sclereids, not expanding much and
retaining large lumina (Fig. 30A,B) filled with tannin.
The walls of sclerified phelloderm cells are polylamellate,
lignified and birefringent.
«
8
~m
Abundant minute crystals
long), mostly hexagonal prismatic in shape, are
found in the wall
of phelloderm cells throughout.
Phellem
cells are narrowly rectangular in TS and RLS, and 4-6 sided
in TLS, with tannin contents (Fig. 30D).
thin (Fig. 30e).
Their walls are
Fig. 27
Dacrydium cupressinum
A.-B.
General view of the living bark
TS(LM) x 60. The top of Fig. 27A
joins
bottom of Fig. 27B.
Xylem (Xy) and vascular cambium
(Vc) at the bottom of Fig. 27A;
ray (R-R'); ray sclereid (RSc);
sclereids (Sc) appear in the
outer part of the conducting
phloem, distributed randomly,
mostly with indistinct lumina
and are very abundant in number;
phelloderm (Pd); phellem (Pm).
The un
lIed arrow in Fig. 27A
indicates approximately the
extent of the conducting phloem.
bark
Fig. 28
Dacrydium cupressinum bark
A.
General arrangement of the phloem cells
near the vascular cambium - TS(LM) x
310;
short tangential rows of axial
parenchyma cells (P) separated by
1-5 other cells made up of sieve cells
(S) and fibres (F) interspersed with
each other;
ray (R-R'). Most axial
parenchyma cells with dark tannin
contents;
some without. Note the
square to rectangular shape of sieve
cells, the round to elliptical shape
of axial parenchyma cells, the
rectangular shape of ray cells and
the narrowly rectangular shape of
fibres.
B.
Sieve cells showing sieve areas in
single file on radial wall - RLS(SEM)
x 1 050.
Note the axial parenchyma
cell (P) (between the two sieve cells)
with the corrugated radial wall,
and crystals (arrowed) in the wall
of the sieve cells, appearing as bulges.
c.
A sieve area with a vertical and
horizontal diameters of 15 ~m
and
14 ~m
respectively - RLS(SEM) x 2 690.
D.
A section of the phloem near the
vascular cambium, showing dividing
axial parenchyma mother cells TLS(LM) x 310. Note the complete
radial wall (unlabelled arrow) ,
the incomplete radial wall (I),
transverse wall (T) and oblique wall
(0); normal axial parenchyma cells
with tannin contents (P);
note the
round shape of the cells in the
rays (R).
E.
A section of the phloem near the
vascular cambium,
showing a long
parenchyma cell (arrowed) where the
parenchyma mother cell did not
undergo division - RLS(SEM) x 60.
F.
A T-shaped parenchyma cell - RLS(LM)
x 625. The part of the cell labelled
A is in the axial system and the
part labelled R is in the ray system.
G.
A tannin-filled L-shaped parenchyma
cell - RLS(LM) x-310. The part
labelled A is in the axial system
and the part labelled R' is in the
ray system;
ray cells (R).
The
arrow at the bottom right points to
the outside of the stem.
um cupressinum bark
Fig. 29
A.
A section of the phloem, showing normal
axial parenchyma cells (P) and one with
a corrugated radial wall (PI).
The pronounced protrusions are arrowed.
B.
non-sclerified axial parenchyma
(E) - TS(LM) x 160; unexpanded
al
parenchyma (p);
sclereids (Sc);
fibres (F).
c.
Sclerif
ray (R') and axial (PI)
parenchyma cells - TLS(LM) x 625;
non-sc
ed ray (R) and axial
parenchyma cells (P). Note the bu
(unlabel
arrows) of crystals in
wall of axial parenchyma cells.
D~
An area of the phloem, showing crystals
in the
lular spaces between
ray (R) and longitudinal cells RLS(SEM) x 500. The area enclosed in
the box is enlarged in Fig. 29E.
S
cells (S);
al parenchyma (P).
E.
Enlargement of the area enclosed in
the box in Fig. 29D, showing crystals
(arrowed) in
inter-cellular
spaces between ray (R) and longitudinal
cells - RLS(SEM) x 1 000;
sieve cell
(S) •
F.
Layers of fibre wall - TS(SEM) x 2 750;
note the two main lamellae: one thin
lamella (1) on
outside and one
thick lamella (2) on the inside; wall
of adjacent cells (W).
G.
Macerated sclereids, showing the
irregular shape, tending to be
slightly elongated -(LM)x 60.
Note the
branches (arrowed) that would have grown
into the longitudinal cells.
H.
A growing sclereid (Sc) sending branches
(unlabelled arrows) into longitudinal
cells - TLS(LM) x 310; rays (R) i
note
tannin-filled ray cell (tn) likely to
be part of an L or T-shaped parenchyma.
Fig . 29
Fig. 30
Dacrydium cupressinum bark
A.
Part
the periderm - RLS(SEM} x 260.
Phelloderm (Pd);
phellem (Pm);
note
the sc
fied phelloderm cells
elongated in the radial direction
(arrowed).
There is a break at
phel
layer in this specimen.
B.
Phelloderm cells under polarized
light, showing crystals (arrowed)
in the
wall - TLS(LM} x 625.
Note
sclerified phelloderm cell
(Sc) .
c.
Phellem cells, showing their thin
walls - RLS(SEM} x 2 625. Arrow
points to the outside
the stem.
D.
Phellem cells, showing their 4-6
sided shape and their tannin contents
- TLS(LM} x 160.
44
Dacrydium intermedium Kirk.
Specimens were col
at breast height, the
and living bark
Location of trees
(1)
cknesses being:
Diameter
(cm)
Living
thickness
19.3
4.2
(2 ) Inangahua West
State Forest
20.1
4.4
(3) Mokihinui State
Forest
16.9
5.1
(4 ) Inangahua West
State Forest
21.3
5.8
(5) Mokihinui State
Forest
23.0
4.2
(6 ) Mokihinui State
Forest
13.0
3.5
State Forest
(rom)
The conducting phloem consists of ray parenchyma
and tangential rows of axial parenchyma (Fig. 31A,B, 32A)
separated by about 2-4 rows of mainly sieve cells (Fig. 31D),
sometimes replaced by individual parenchyma.
Sometimes,
fibres are present in the phloem near the vascular cambium
in which case they replace some sieve cells too.
non-conducting
and the outer part of the conducting
phloem, some to many sclereids and more f
appear randomly,
In the
s begin to
abundance increasing centrifugally
(Fig. 31A , B, 3 2A) .
conducting phloem is about 0.3-0.5
rom wide (Fig. 31A, 32A).
Sieve cells are rectangular in TS
collapsing in the non-conducting phloem.
prismatic crystals «
8
~m
~m
long), mo
. 31D,E),
Minute hexagonal
long) are sometimes found ln
the radial wall of some sieve cells.
(25-90
(F
Large c
hexagonal prismatic
tals
shape too,
45
are present in some sieve cells (Fig. 31E)
filling up the whole cell.
sometimes
I
Sieve areas are about 5-10
~m
in diameter l mostly on the radial walls in single file
(Fig. 32B).
Axial parenchyma cells are square to rectangular
in TS in the region close to the vascular cambium where it
is sometimes difficult to distinguish them from sieve cells
(Fig. 31D).
They eventually become round (Fig. 3
RLS and TLS,
appear rectangular.
).
In
Axial parenchyma cells
close to the vascular cambium are without contents (Fig.
31D,E) but are mostly filled with tannin eventually (Fig. 31A,
B), especially in the non-conducting phloem.
In the non-
conducting phloem and outer part of the conducting phloem,
some axial parenchyma cells seem to develop into fibres and
others develop into s
reids (Fig. 32E).
Some sclereids
grow a few or many times larger than the original parenchyma
cells, tending to be elongated, while others remain about
the same
(Fig. 3
ze and shape, developing only a sclerified wall
).
Some non-sclerified axial parenchyma cells
expand slightly towards the phelloderm as seen in TS
(F
. 31A,B), remaining rectangular in both TLS and RLS.
Minute hexagonal prismatic crystals «
8
~m
long) sometimes
occur in the radial wall of some axial parenchyma cells.
Phloem rays are uniser
,very occasionally part-
biseriate and 1-18 cells high (up to 20 counted).
They
appear rectangular in TS and RLS and round in TLS, some
becoming slightly oval in TLS in the outer phloem, upon
dilation.
species.
Dilation is not a pronounced feature in this
A number of ray cells undergo sclerification
(Fig. 32C), some growing irregularly (tending to be isodiamet
) to many times the original size while others
remain almost the original size
shape.
46
Fibres appear rectangular (with long axes ln the
tangential direction)
(Fig. 31E) to square in TS, having
an elongated form with pointed ends.
Some fibres seem to
develop secondarily from axial parenchyma cells in the
outer part of the conducting phloem and also in the nonconducting phloem.
Their wall is thick with very small,
almost indistinct lumina (Fig. 32D), and seems to be
lignified and birefringent.
lamellae:
It is made up of two maln
one thin lamella on the outside and one thick
lamella on the inside (Fig.32D).
Phloem sclereids are developed from both ray and
axial parenchyma cells.
Development begins in the outer
part of the conducting phloem.
They are either (1)
isodiametric, sometimes tending to be elongated in the
longitudinal direction and a few to many times larger than
the original cells, or (2) of more or less the same shape
and size as the original cells.
They are distributed
ramdomly, sparse (Fig. 32A) to abundant (Fig. 31A,B) in
number.
fringent.
Their wall is polylamellate, lignified and bireThe large sclereids tend to have large empty
lumina while the smaller sclereids have lumina that are
small or indistinct.
The periderm consists of about 4-7 layers of phellem,
one layer of phellogen and about 5-8 layers of phelloderm.
Phelloderm cells are isodiametric to rectangular in TS
(Fig. 33A) and RLS, and 4-6 sided in TLS.
They have
thin walls (Fig. 33A) and are mostly filled with tannin
(Fig. 31B, 32A, 33B).
Very occasionally, a few phelloderm
cells develop into sclereids remaining rather isodiametric
in all planes, growing to a few times larger than the
original phelloderm cells.
Sometimes, abundant minute
47
crystals«
3
~m
long), mostly hexagonal prismatic in
shape, are found in the wall of phelloderm cells,
throughout.
bark of
Lenticels seem to
very plentiful in the
Crys
Dacrydium inr.ermedium.
s are very abundant
in the wall (in the region of the middle lamella) of
phelloderm cells under lentice
slightly larger size (up to 10
~m
(Fig. 33C) and are of
long) than those else-
llem cells are square to
where in the phelloderm.
rectangular in TS, rectangular in RLS and 4 6 sided in
TLS.
The
tangential wall of most phellem cells is
thicker than the outer tangential wall (Fig. 33D) and
birefringent (Fig. 33C).
walled.
A
1S
phellem cells are thin-
Cone-shaped structures protrude from the inner
tangential wall into the lumina (Fig. 33D).
The wall of
the outermost 1 or 2 layers of phellem seem to be slightly
lignified.
Phellem
Is are filled with tannin (Fig. 33A).
Fig. 31
Dacrydium intermedium bark
A.-B.
General view of the living bark where
sclereids (Sc) are abundant TS(LM) x 60; the top of Fig. 31A
joins the bottom of Fig.31B; this
specimen was broken at the vascular
cambium (Vc); rows of axial
parenchyma (p);
(r-r');
expanded axial parenchyma cells (e);
phelloderm (pd) filled with tannin;
phellem (pm). Axial parenchyma
cells near the vascular cambium are
without contents but are mostly
fil
with tannin further out.
The unlabelled arrow in Fig. 31A
indicates approximately the extent
of the conducting phloem.
c.
Three macerated sclerified parenchyma
cel
in a strand (arrowed) (I.L\1)
160. These sclereids have
remained the same size and shape as
the original cells.
D.
phloem
Is in the immediate
vicinity of the vascular cambium TS(LM) x 625; tangential rows of
parenchyma cells (p) separated
by about 2-4 (in this case 2) rows
of sieve
Is (s). Both axial
parenchyma and sieve cells are
rectangular in sh
and dif cult
to distinguish from each other.
Note that the parenchyma are
without tannin contents.
E.
phloem cells in the outer part of
the conducting ph
- TS(LM)
x 625; rectangular-shaped fibre (f)
rectangular-shaped sieve cells (s) i
round-shaped axial parenchyma (p);
ray (R-R') i
sclereids (Sc) of the
same shape and size as the axial
parenchyma cells from which they
developed; crystals (x) in s
cel
i
Fig. 32
Dacrydium intermedium bark
A.
General view of the living bark where
sclere
(Sc) are
- TS(LH)x 60;
xylem (Xy);
vascular cambium (Vc);
tangential rows of axial parenchyma
(P);
rays (r-r');
loderm (Pd)
filled with tannin;
phellem (Pm).
Unlabel
arrow indicates approximately
the extent of the conducting phloem.
B.
Sieve areas in single
Ie - RLS(SEM)
x 2 750; the top sieve area has a
vertical and horizontal diameter of
ca. 4 and 5 ~m
respect
ly while the
bottom sieve area has a vertical and
horizontal diameter of ca. 7 and 8 ~m
respective
c.
A sclerifying ray cell (arrowed) TLS(SEM) x 1 100; non-sclerified
ray cell (r).
D.
Fibres, showing the 2 main lamellae
of the wall: one thin lamella on
the outside (1) and one thick lamella
on the ins
(2) - TS(SEM) x 2 625;
note the small lumina (1).
E.
Sclereids (Sc) developing from axial
parenchyma cells in the outer part
of the conducting phloem - TS(LM)
(f);
axial parenchyma
x 310;
cells (p);
sieve cells (s).
Fig. 33
Dacrydium intermedium
bark
A.
Phelloderm cells (D) showing their
thin walls and rectangular shape TS(SEM) x 1 100; phellogen (N);
phellem (M). Note that the radial
wall (Q) indicates that an anticlinal
division has taken place. Unlabelled
arrow points to the outside of the
stem.
B.-C.
A view of a lenticel without (Fig. 33B)
and with (Fig. 33C) pol
zed light,
showing abundant birefringent crystals
(X)
the walls of phelloderm cells RLS{LM) x 60; phloem (ph) i phelloderm
(d); phellem (m) ; large crystals in
the phloem (Z);
complementary tissue
(Ct). Note the birefringent phellem
cell wall (unlabelled arrows in Fig.33C)
and also the tannin contents of the
phelloderm and phellem cells (Fig. 33B).
D.
Phellem cells, showing their wall TS(SEM) x 970; middle-lamella (ml);
note that the inner tangential wall
(I)
thicker than the outer
tangential wall (0) and also the
cone-shaped structures protruding
into the lumina from the inner
tangantial wall (unlabelled arrows)
(though not very clear) .
Fig.
48
Dacrydium colensoi
Hook.
Specimens were collected at breast height, the
diameters and living bark thicknesses being:
Location of trees
Diameter
(em)
Living bark
thickness (mm)
(1 ) Maimai State Forest
25.0
8.0
(2 ) Inangahua West
State Forest
14.1
7.8
(3) Inangahua ~\]est
State Forest
28.8
4.8
(4) Mokihinui State
Forest
25.3
7.5
The conducting phloem consists of ray parenchyma
and tangential rows of axial parenchyma (Fig. 34A)
separated by 4-6 (occasionally more or
s) rows of
Is interspersed with fibres at random or in
sieve
short tangenti
rows (Fig. 34B).
Sclereids are present
at random in the outer part of the non-conducting phloem,
occasionally in the inner phloem.
The conducting phloem
is about 1.7-2.0 rom wide (Fig. 34A).
Sieve cells appear rectangular in TS (Fig. 34C)
with some minute crystals «
4
~m
long) in their wall.
The lumina of some sieve cells are
crystals (ca. 10-30
ling up the who
are most
~m
long)
I
lled with large
sometimes many crystals
cell (Fig. 34D).
The crystals
of hexagonal prismatic shape.
However, no
crystals are found in the lumina of sieve cells in the
immediate vicinity of the vascular cambium.
sieve cells are devoid of crystals.
about 5-8
single
~m
Walls of
Sieve areas are
in diameter, mostly on the radial wall in
le (Fig. 34E).
49
Axial parenchyma cells are isodiame
c in TS
(Fig. 34B) and rectangular in RLS and TLS.
mostly filled with tannin.
crysta
It seems that there are no
in the wall or lumina of
Some parenchyma cells
They are
1 parenchyma cells.
rm sclereids, but only growing to
a few times the original size, remaining rather elongated
in shape.
Towards the phelloderm, some parenchyma cells
expand, but remain isodiametric in TS
(Fig. 35A) and
rectangular in RLS and TLS.
phloem rays are uniseriate, rarely part-biseriate
and are 1-10 (up to 18 counted)
Is high.
They are
rectangular in TS and RLS and round to elliptical in TLS.
Towards the phelloderm, some ray cells undergo dilation
becoming isodiametric, tending to be somewhat oblong (with
long axes
the tangential direction) in TS and TLS and
isodiametric ln RLS, sometimes with the formation of a
radial cross
-biseriate.
«
4
~m
1
(Fig. 35A);
ray thus becoming
Minute hexagonal prismatic crystals
long) are sometimes found in the inter-cellular
spaces between ray cells and longitudinal cells.
Some
ray cells form sclereids, growing to a few times the
original size.
Fibres are rectangu
TS
to narrowly rectangular in
(with long axes in the tangential direction) (Fig. 34B)
having elongated form with pointed ends.
Their walls are
thick, lignified and birefringent, and seem to be made up
of two main lamellae:
one thin lamella on the outside
and one thick lamella on the inside
(Fig. 35B).
The lumina
are very narrow.
Phloem sclereids are formed from axial and ray
parenchyma, growing to a few times the original size,
50
tending to have elongated shapes (Fig. 35C) oriented
in the longitudinal direction, mostly with almost
indistinct lumina (Fig. 35B).
have small empty lumina.
lamellate, ligni
However, some sclereids
Sclereid walls are poly-
ed and birefringent.
Phloem sclereids
are sparse to moderate in number (Fig. 34A,B).
The primary cortex seems to persist for a long
time on the stem. Cortical cells are oblong to elliptical,
sometimes rectangular to isodiametric in TS and TLS
(with long axes in the tangential horizorital dire2tion
(F
• 35C) and isodiametric in RLS.
Some of the cells
become sclereids, mostly with indistinct lumina but do
not expand to any great extent. Sclereids in the cortex
tend to be in short tangential bands or groups, a
cells in a local area sclerifying together.
Cortical
cells are sometimes difficult to distinguish
phelloderm cells.
The periderm comprises about 25-45 layers phellem,
one layer phellogen and about 6-20 layers phelloderm.
Phelloderm cells produced by phellogen cells derived
from cortical cells initially appear rectangular or
elongated in TS and TLS (with long axes in. the horizontal
tangential direction)
(Fig. 35E) and isodiametric with
thickened non-lignified walls in RLS.
In older stems
where the phellogen is derived from phloem parenchyma,
the phelloderm cells initially appear rectangular to
almost square in TS and RLS, and 4-6 sided in TLS.
In
both younger and older stems, the phelloderm cells
eventually expand, becoming isodiametric in all planes
(F
. 35H).
Some become sclereids, growing to a few
times larger (Fig. 35H), remaining rather isodiametric
51
in all planes, mostly with indistinct lumina.
cells are mos
«
4
~m
filled with tannin.
Phelloderm
Some minute crystals
long), mostly of hexagonal prismatic shape, are
found in the wall
abundance under
phelloderm cells and they are
~n
Phellem cells are narrowly
icels.
rectangular to almost square in TS and RLS, irregularly
polygonal to regular
4 6 sided in TLS (Fig. 35F,G).
Those phellem cells produced by phellogen cells derived
from cortical cells
in TLS
(Fig. 35G).
ably appear irregularly polygonal
Phellem
mostly without contents.
Is are thin-walled (Fig. 36A) ,
However, some phellem cells,
especially some in the outer
have slightly thicker
inner tangential wall with cone
protruding into the lumina
structures
• 3GB).
Fig. 34
Dacrydium colensoi
A.-B.
General view of
living bark TS(LM) x 60. The top of Fig. 34A
joins the bottom of Fig. 34B;
xylem (Xy);
vascular cambium
(Vc) i
tangential rows of axial
parenchyma (P);
rays (r-r')j
sclereids (Sc), sparse in
number; primary cortex (pc);
phelloderm (Pd);
phellem (Pm).
The unlabel
arrow in Fig. 34A
indicates approximately the
extent of the conducting phloem.
c.
General arrangement of phloem
cells -TS(LM) x 625; tangential
rows of axial parenchyma (p) i
fibres (f) in short tangential
rows;
sieve cells (s) i
crystals
(x) in sieve cells. Note
rectangular shape of sieve cells,
isodiametric shape ofaxi
parenchyma and rectangular to
narrowly rectangular shape of
fibres.
D.
A macerated sieve cell, observed
under polarized light showing
the lumina fil
with crystals
(arrowed) - (LM)x 160.
E.
Sieve areas in s
file, in
two adjacent sieve cells The vertical
RLS(SEM) x 2 625.
and horizontal diameters are: for
the
ft cell (top to bottom) ,
ca. 5 and 6 urn, ca. 5 and 8 urn,
ca. 6 and 7 urn and ca. 4 and 6 urn;
for the
ght cell (top to bottom),
ca. 5 and 8 urn, ca. 6 and 7 urn
and ca. 6 and 8 urn.
bark
Fig . 34
Fig. 35
Dacrydium colensoi
bark
A ray (r-r') in the outer part of the
non-conducting phloem, showing dilation
(D), with formation of radial cross
walls (arrowed) - TS(LM) x 160;
fibres (f) i
axial parenchyma cells (p);
expanded axial parenchyma cells (e);
sclereids (Sc).
B.
Fibres, showing the two main lamel
of the wall:
one thin lamella on the
outside (1) and one thick lamella on
the inside (2) - TS(SEM) x 2 750;
wall of adjacent cell (W).
Note the
almost indistinct lumina (unlabelled
arrows) .
c.
A macerated phloem sclereid, showing
its elongated shape -(LM)x 160.
D.
A section of the primary cortex, showing
the oblong to elliptical, rectangular
to isodiametric shapes of the cells TLS(LM) x 60;
cortical sc
ids (Sc).
E.
Phelloderm cells close to the phellogen
in a younger stern where the phellogen
is derived from cortical cells rectangular
TLS(LM) x 160. Note
to elongated shape, oriented in the
horizontal direction.
Phellem cells, with 4-6 sided shape TLS(LM) x 310.
G.
Phellem cells produced by a phellogen
derived from cortical cells, showing
the irregularly polygonal shape TLS(L!1) x 310.
H.
Phelloderm cells away from the
phellogen, showing their isodiametric
shape - TLS (Ll1) x 160.
Note the
sclerified phelloderm cell (Sc), a
few times larger than the original
(non-sclerified) cell.
Fig. 36
Dacrydium colensoi
A.
Thin-walled phellem cells, showing
their walls
TS{SEM) x 2 625.
B.
Phellem cells with thicker inner
tangential wall (I) - TS{SEM) x
2 625; outer tangential wall of
inner cell (0) i
middle-lame
(ml). Note the cone-shaped structure
(e) protruding into the lumina from
the inner tangential wall.
bark
Fig. 36
52
Phyllocladus alpinus
Hook. f.
Specimens were collected at breast height, the
diameters and living bark thicknesses being:
Location of trees
Diameter
(em)
Living bark
thickness (mm)
(1) Maimai State Forest
14.7
5.1
(2 ) Maimai State Forest
12.4
6.4
(3 ) Inangahua West
State Forest
15.8
5.5
The phloem consists of sieve cells, axial parenchyma
cells and fibres arranged ln regular tangential rows,
and ray parenchyma cells and sclereids.
Tangential rows
of axial parenchyma cells (Fig. 37A) usually have 1-2 rows
of sieve cells on each side.
These parenchyma-sieve cell
rows are usually separated by a row of fibres
(Fig. 37A)
i
deviations occur sometimes leading to offset rows, short
rows and individual scattered cells.
Scattered sclereids
start to develop at random from ray and axial parenchyma
cells (but mainly from ray cells) in the non-conducting
phloem, their abundance increasing centrifugally.
The
conducting phloem is about 1.0-1.4 mm.
Sieve cells are rectangular in TS
(Fig. 37C) and they
collapse in the radial direction when they cease to function
(Fig. 37D).
latter.
< 3
~m
Those adjacent to sclereids are crushed by the
Minute variously-shaped prismatic crystals (mostly
long) are found in their radial walls.
Occasionally,
a few small to large crystals (variously-shaped prisms, ca.
10-25
~m
long) are located in the lumina of sieve cells.
Sieve areas are about 5-9
~m
in diameter (Fig. 38A), mostly
on radial wall in single file.
53
Axial parenchyma cells are round to oval in TS
(Fig. 37C), rectangular in RLS and TLS, mostly without
tannin.
Some axial parenchyma cells develop into sclereids
(Fig. 38B,C), growing a few to many times the original
size, isodiametric to elongated in shape. In some areas
in the non-conducting phloem, radial files of axial
parenchyma cells expand and divide, becoming rather isodiametric in all planes (Fig. 37A,B, 38D).
Centrifugally,
other parenchyma cells between the initial files eventually
expand too.
(mostly < 3
~m
A few variously-shaped prismatic crystals
long) are found in the radial wall of some
axial parenchyma cells.
Occasionally, a few small to large
variously-shaped prismatic crystals (ca. 10-25
~m
long) are
located in the lumina of axial parenchyma cells.
Phloem rays are uniseriate, rarely part-biseriate
and are about 1-14 cells high.
The ray cells appear round
in TLS (Fig. 38C), rectangular in TS (Fig. 37C) and RLS.
Eventually some ray cells expand many times, sometimes
dividing, becoming rather isodiametric in all planes
(Fig. 37A,B, 38B,D,E).
These are associated with the radial
files of expanding axial parenchyma cells described above.
Some ray cells in such areas develop into sclereids (Fig.
38E), growing many times with rather isodiametric shapes.
Fibres are rectangular in TS (Fig. 37C), having
elongated form with pointed ends.
Their wall is thick,
lignified, birefringent and is made up of two main lamellae:
one thin lamella on the outside and one thick lamella on the
inside (Fig. 38F).
indistinct.
The lumina of fibres are small to almost
Abundant minute to small variously-shaped
prismatic crystals
«
8
~m
long) are located in the wall of
fibres In the region of the middle-lamella, mostly in the
radial wall (Fig. 38F,G).
54
phloem sclereids are developed from some ray and
axial parenchyma cells in the non-conducting phloem.
They grow to many times the size of the original cells,
with isodiametr
to elongated shapes, oriented in the
longitudin
Sclereids are distributed at
random and are sparse to moderate in number (Fig. 37A,B),
possessing a polylamellate wall which is lignified and
birefringent.
The
lumina are mostly indistinct;
however
some have small empty lumina.
The primary cortex
a long time.
In all
seems to persist on
speClmens studied,
cortex is present and
Is.
stem for
primary
phellogen is derived from cortical
Cortical cells appear rectangular (with
axes
in the horizontal tangential direction) to isodi
TS and TLS and isodi
in
c in RLS (Fig. 38H,I), some
being filled with tannin,
A number of cortical cells develop
into sclereids at random (sometimes in groups)
(Fig. 37B),
growing a few to many times the size of the original
Is,
remaining rather rectangular (with long axes in the
tangential horizontal direction) to isodiametric (
anes), mostly with indis
all
t lumina (Fig. 38H). Some of
sclereids have walls that are made up of only a few
with large empty lumina (Fig. 381), others have
single lamellaed thickened lignified wall.
of variously-shaped prisms· (5 40
llular spaces.
(Fig. 39A).
ca. 60
(F
~m
~m
Some crystals,
long) seem to lie in the
Sometimes they appear as aggregates
Variously-shaped
smatic crystals (up to
long) occur as aggregates in some cortical cells
. 39A).
Occasional lysigenous
diameter 150-250
~m
resin canals, of
are seen to traverse in the tangential
55
horizontal direction.
They appear round to oval in RLS
(Fig. 39B).
The periderm consists of about 5-30 layers of
phellem, one layer of phellogen and about 5-10 layers of
phelloderm.
The first 2-3 layers of phelloderm nearest
the phellogen appear isodiametric to square in TS, isodiametric in RLS (Fig. 39C) and 4-6 sided in TLS and
possess thin walls.
Eventually, they become narrowly
rectangular in TS, and TLS (oriented in the tangential
horizontal direction)
(Fig. 39D), and isodiametric in
RLS, some developing slightly thickened, non-lignified
wall (Fig. 39C).
A few phelloderm cells at random develop
into sclereids but most remain almost the same shape and
size as the original cell, possessing distinct empty lumina
and po
amellate, ligni
ed, birefringent walls (Fig. 39E)
Some phelloderm cells are filled with tannin but the
first 2-3 layers nearest the phellogen are free of tannin
contents.
Variously-shaped prismatic crystals, mostly
minute «
8
~m
long) are found in the wall of some phello-
derm cells, but are in abundance in the wall of those
phelloderm cells under lenticels (Fig. 39F,G).
Phellem cells are rectangular to isodiametric in TS
and RLS, 4-6 sided in TLS (Fig. 39H), sometimes slightly
elongated in the tangential horizontal direction (Fig. 39I)
especially cells of the outer layers and are mostly filled
with tannin.
The outer layers are mostly thin-walled but
the inner layers have cells that possess slightly thicker
inner tangential wall (Fig. 39I) which is slightly birefringent (Fig. 39G).
Cone-shaped structures protrude from
this inner tangential wall into the lumen (Fig. 39J).
Fig. 37
Phyllocladus alpinus bark
A.-B.
General view of the living bark this specimen was
TS(LM) x 60;
broken at the vascular cambium (Vc)
at the bottom of Fig. 37Ai
tangential rows of axial parenchyma
(P) and fibres (F);
rays (r-r l ) ;
expanded and divided parenchyma (E);
sclereids (Sc), mostly associated
with expanded phloem axial and ray
parenchyma, and also in the primary
cortex;
primary cortex (pc);
periderm (pe). Note that phloem
sclereids are sparse to moderate
in number.
The unlabel
arrow
in Fig. 37A indicates approximately
the extent of the conducting
phloem.
c.
General arrangement of phloem cells
near the vascular cambium TS(il1) x 625;
tangential rows
of axial parenchyma (p) with 1-2
sieve cells (s) on each side,
separated by a row
fibres (f);
ray (r-r'). Some off-setting
rows can be seen (the row of
axial parenchyma towards the lower
half of the micrograph).
Note the
rectangular shape of sieve cells,
round to oval shape of axial
parenchyma cells, rectangular
shape of ray cells and rectangular
shape of fibres.
D.
An area in the phloem towards the
non-conducting phloem, showing
collapsing sieve cel
(s)
TS(LM) x 625;
axial parenchyma
cells (p)i
fibres (f)i
crystal
(x) in axial parenchyma cell.
Fig. 38
Phyllocladus alpinus bark
A.
sieve areas - RLS(SEI'1) x 2 750.
The top
sieve area
s a vertical and horizontal
diameter of ca. 6 and 7 ~m
respectively
and the bottom sieve area has a vertical
and horizontal diameter of ca. 5 and 6 ~m
respectively.
B.
An area in the non-conducting phloem,
showing expanded and divided ray cells
(E) and a sclereid (Sc) developed from
axial parenchyma - TS(LM) x 160;
ray
(r-r ' ) i
slightly expanded axial
parenchyma (p).
c.
An axial parenchyma cell developing
into a sclereid (arrowed)
TLS(LM)
x 160. Note the round shape of the
ray cells (r).
D.
Expanded axi
(J) and ray (K) parenchyma
cells - TLS(LM) x 310;
normal ray (R)
E.
An area in the outer part of the nonconducting phloem, showing expanded and
divided axial (J) and ray (K) parenchyma
cells ~ TLS (U1) x 160;
bres (f) i
sclereid (Sc) developed from ray.
F.
Fibres, showing the two main lamellae
of the wall:
one thin lamella on the
outside (1) and one thick lamella on
the inside (2) - TS(SEM) x 2 875.
sieve
ls (s).
Note the crystals (x)
in the region of the middle lamella of
the radial wall
G.
Crystals (X) in the region of the middle
lamella in the radial wall between two
fibres (f) - TS(SEM) x 2 875.
H.
Sclereids (Sc) developed from cortical
cells RLS(SEM) x 1 080.
Note the
indistinct lumina of the sclereids and
the isodiametr
shape of the nonsclerified cortic
cells (C).
1.
Cortical sclereids (Sc) with wal
made
up of only a few larrellce wi th large empty
lumina - RLS(SEM) x 310. Note the
isodiametric shape of the non-sclerified
cortical cells (C).
Fig. 39
Phyllocladus alpinus bark
A.
Aggregates of crystals (Z) in cortical
cells and in the intercellular spaces,
appearing birefringent under polarized
light - TLS(LM) x 160.
B.
Resin canal (Rc) in the primary cortex RLS(LM) x 160;
note the round shape,
tending to be slightly oval.
C.
Phelloderm cells, showing their
isodiametric shape and also their slightly
thickened, non-lignified wall - TS(SEM)
x 1 070.
D.
Phelloderm cells with elongated narrowly
rectangular shape - TLS(LM) x 160.
E.
Phelloderm sclereids (Sc) with distinct
lumina and polylamellate wall - RLS(SEM)
The top sclereid has grown
x 1 050.
larger than the original cell while the
bottom one has remained almost the same
size.
F.-G.
A lenticel viewed with normal light
(Fig. 39F) and polarized light (Fig. 39G),
showing higher accumulation of crystals
(X) between the walls of phelloderm
cells under the lenticel - RLS(LM) x 60;
sclereids (S);
phellem cells with
thicker inner tangential wall are
slightly birefringent (Q).
H.
Phellem cells with 4-6 sided shape TLS(LM) x 625.
1.
Phellem cells that are slightly elongated
in the tangential horizontal direction TLS(LM) x 310.
J.
Phellem cells with a slightly thicker
inner tangential wall (I), with coneshaped structures (Co) protruding from
this wall into the lumina - TS(SEM) x
outer tangential wall (0);
2 750;
middle lamella (ml).
The unlabelled
arrow at the bottom right points to the
outside of the stem.
Fig. 39
56
Carr.
Phyllocladus glaucus
Specimens were collected at breast height, the
diameter and living bark thicknesses being:
Living bark
thickness (mm)
Diameter
(em)
Location of trees
(1 ) Puketi State Forest
25.6
10.4*
(2 ) Puketi State Forest
34.3
9.8*
(3) Puketi State Forest
27.2
8.2*
(4 ) Puketi State Forest
25.5
14.0
(5) Puketi State Forest
33.0
11. 2
(6) Puketi State Forest
31. 0
11.1
*
Note:
Samples 1, 2 and 3 were collected without phellem
layers, which broke off at the phellogen layer.
The phloem consists of Sleve cells,
parenchyma
cells and fibres arranged ln regular tangential rows, ray
parenchyma cells and sclere
Tangential rows of axial
parenchyma cells usually have 1-2 rows of s
each side.
cells on
These parenchyma-sieve cell rows are usually
separated by a row
be absent or
fibres.
Sometimes a fibre row may
aced by single fibres.
Other deviations
occur too, leading often to off-set rows, short rows and
individual scattered cells.
Scattered sclereids start to
form at random from ray and axial parenchyma cells (but
mainly from ray parenchyma cells) in the non-conducting
phloem, their abundance increasing centrifugally.
The
conducting phloem is about 1.6-3.0 mm wide.
Sieve cells are rectangular
collap
phloem.
«
TS (Fig. 40E), becoming
in the radial direction In the non-conducting
Minute variously-shaped prismatic crystals
4 Vm long)
(Fig. 41A) are found
the radial wall of
57
some sieve cells.
The lumina of sieve cells seem to be
free of crystals.
Sieve areas are about 5-13
~m
in
diameter (Fig. 4lB), occurring mostly on radial walls in
single file.
Axial parenchyma cells are round in TS (Fig. 40E),
tending to be oval and rectangular in RLS and TLS, and are
without contents.
short radial fi
Some axial parenchyma cells in certain
s divide and expand markedly, becoming
rather isodiametric in all planes (Fig. 4lC).
Centrifugally,
other parenchyma cells between the initial files eventually
expand too.
Some axial parenchyma cells, especially some
among expanded parenchyma develop into sclereids, growing
a few to many times the size of the original cells, becoming
isodiametric to elongated in shape.
variously-shaped prismatic crystals
Very few minute
10
«
~m
long) are
found in the radial wall of axial parenchyma cells.
Occasionally, a few small to large crystals, of various
shapes (ca. 5-15
parenchyma
~m
long) are found in the lumina of axial
Is.
Phloem rays are uniseriate, rarely part-biseriate and
1-20 cells high (up to 28 counted).
Ray cells appear round
in TLS and rectangular in TS and RLS.
Eventually, some
rays expand many times and divide, becoming rather isodiametric in all planes (Fig. 40A,B 4lD).
These are usually
associated with the radial files of expanding axial parenchyma
cells as described above.
Ray cells at the margin of rays
seem to 'grow intrusively' in the longitudinal direction
(as seen in TLS), pushing longitudinal cells apart and
growing between them.
Some ray cells develop into
sclereids, growing to many times the size of the original
cells with rather isodiametric shapes.
Such sclerified
ray cells are usually associated with the expanded ray cells.
58
Fibres are rectangular in TS (Fig. 40E), having
elongated form with pointed ends.
Their wall is thick,
lignified and birefringent and is made up of 2 main
lamellae:
one very thin lamella on the outside and one
thick lamella on the inside (Fig. 41E).
are small to almost indistinct.
prismatic crystals «
4
~m
long)
Their lumina
Minute variously-shaped
(Fig. 41A) are located
in the wall of fibres, in the region of the middle lamella;
especially abundant in the radial wall.
Phloem sclereids are developed from some ray and
axial parenchyma cells (but mainly from ray cells) in the
non-conducting phloem, growing a few to many times the
size of the original cells with isodiametric to elongated
(in the longitudinal direction) shape.
They are distributed
at random and very sparse to sparse in number, mostly with
small to indistinct lumina.
Their wall is polylamellate,
lignified and birefringent.
Some sclereids have thin walls
of only a few lamellae, possessing large empty lumina.
In all specimens studied, the primary cortex was
present.
Thus, it seems that the primary cortex persists
for a long time on the stem.
Cortical cells are rectangular
or oval (oriented in the tangential horizontal direction)
to isodiametric in TS and TLS and isodiametric in RLS
(Fig. 41G).
They are devoid of tannin contents but a few
cells contain aggregates of crystals of various shapes
«
60
~m
(ca. 5-30
spaces.
long) .
~m
Variously-shaped prismatic crystals
long) are often found in the intercellular
At random, some cortical cells develop into
sclereids, either with thin walls (of a few lamellae) and
large empty lumina or thick polylamellate walls with smaller
or almost indistinct lumina (Fig. 41G).
They grow to a few
59
times the size of the original cells, remaining more or
less the same shape.
The walls of both sclereid types
are lignified and bire
ingent.
Occasional lysigenous-
type resin canals of 0.25-1.25 rom diameter are observed
ln the tangential horizontal direction, appearing round
to oval in RLS (Fig. 42A-D).
The periderm comprises about 80-150 layers
phellem,
one layer of phellogen and about 8-20 layers of phelloderm.
The first 2-4 layers of phelloderm nearest the phellogen
appear isodiametric to square in TS, isodiametric in RLS
and 4-6 sided in TLS and are without tannin contents.
Eventually, most phelloderm cells become rectangular to
narrowly rectangular in TS and TLS (oriented in the
tangential horizontal direction) and isodiametric in RLS,
filled with tannin.
Phelloderm walls are thickened, some-
times appearing slightly lignified, but not polylamellate
(Fig.42E).
A few phelloderm cells develop into sclereids
at random.
Some of the sclereids remain the same shape
and size as the original cells while others grow a few to
many times the original size, becoming isodiametric in
planes.
Minute to small variously-shaped prismatic
crystals (mostly < 5
phelloderm cells.
Phellem
1
~m
long) are found in the wall
They are most abundant under lenticels.
Is are narrowly rectangular in TS and RLS,
and 4-6 sided to irregularly polygonal in TLS (Fig. 42F)
Their wall is thin (Fig. 42G).
slightly birefringent.
Some phel
cell wall is
Most phellem cells are empty while
some are tannin-filled (Fig. 40D).
Fig. 40
Phyllocladus
A.-C.
General view of
living bark TS(~l)
x 60; this specimen was broken
at the vascular cambium (Vc) i
tangential
rows of axial parenchyma (P) with 1-2
rows of sieve
Is on either side and
tangential rows of f
s (F);
rays
(r-r'); expanded and divided axial (AI)
and ray (R) parenchyma;
sclereids (Sc),
associated with expanded and divided
parenchyma cells, very
se to sparse
in number; primary cortex (pc);
phelloderm (pd). The
1
layers
were detached at the phellogen (pn)
during specimen col
The
unlabelled arrow in Fig. 40A indicates
approximately the extent of the
conducting phloem.
D.
General view of phellem cells - TS(LM)
x 60. Note that the outer 1
s (0)
are filled with tannin.
E.
General arrangement of ph
s TS(LM) x 160; tangential rows of axial
parenchyma (p) with
2 rows
sieve
cells (s) separated by a row of fibres
(f) i
some deviations can be seen to the
top half on the left of the micrograph
with individual fibres;
rays (r-r').
Note the rectangular shape of sieve
cells, the round shape of axial parenchyma
cells and the rectangular shape of
fibres.
bark
Fig. 41
Phyllocladus glaucus bark
A.
Variously-shaped prismatic crys
s
(arrowed) typical of those from the
wall of sieve cells and fibres RLS(SEH) x 2 750.
B.
A sieve area - RLS(SEM) x 5 000.
The vertical and horizontal diameters
are ca. 9 and 11 ~m
respectively.
C.
Expanding and dividing axial parenchyma
cells (E) 1 showing their isodiame
shape - TS(SEM) x 565; fibres (f) i
unexpanded axial parenchyma (p).
D.
Expanding and divid
ray parenchyma
cells (E), showing
r isodiametric
shape
TS(LM) x 160;
rays (r-r');
fibres (f) i
axial parenchyma (a).
E.
Fibre, showing the two main lamellae
of
wall: one very thin lamella on
the outside (1) and one thick lamella
on the inside (2) - TS(SEM) x 5 500;
wall of adjacent sieve cell (W).
F.
Crystals (arrowed) in
intercellular
space between cortical ce s - TLS(LM)
x 625.
G.
An area of the primary cortex showing
sclereids with thick polylamellate wall
(Q) and
with thin wall of a few
lamellae and large lumina (L) - RLS(LH)
x 160; note the isodiametric shape of
the normal cortical cel
(n) .
Fig. 41
Fig. 42
Phyllocladus glaucus bark
A.-D.
Resin canals in the different stages of
development:
A. - RLS(LM) x 310;
spe
izing;
cells dividing and
B. - RLS(LM) x 310;
the central cells
undergoing lysis, opening up the
canal (Rc);
epithelial cells (H);
C. - RLS(LM) x 60;
a large developing
res
canal (Rc) , with ce s
undergoing lysis (arrowed);
epithelial cells (H);
normal
cortical cells (n);
D. - RLS(SEM) x 105;
a matured resin
canal (Rc);
note some central
cells sti
left (unlabelled
arrows);
epithelial cells (H);
normal cortical cells (n).
E.
Phelloderm cells, showing their
isodiametric to square shape, with
thickened but non-polylamellate walls
RLS(SEM) x 1 050.
F.
Phellem ce s, showing their 4-6 sided
to irregularly polygonal shape TLS(LM) x 310.
G.
Phellem cells, showing their thin wall TS (Sm·1) x 2 750.
Fig. 42
60
Phyllocladus tr ichomanoides D. Don in Lamb
Specimens were collected at breast height, the
diameter and living bark thicknesses being:
Living bark
thickness (rom)
Diameter
(em)
Location of trees
(1 ) Puketi State Forest
32.8
8.8
(2) Puketi State Forest
39.5
8.5
(3) Puketi State Forest
33.5
8.8
The phloem consists of s
cells, axial parenchyma
cells and fibres, arranged
rows and ray parenchyma
regular tangential
Is and s
ereids.
Tangential
rows of axial parenchyma cells u
have one, sometimes
two rows of sieve cells on each s
These parenchyma-
sieve cell rows are usually separ
by a row of fibres
(Fig. 43A,B,D).
Sometimes a f
row may be absent in
an area or replaced by single fibres.
deviations
occur too, leading often to off-set rows, short rows and
individual scattered cells (Fig. 43D).
start to form at random from ray and
no~cdutig
in the
sclereids
al parenchyma cells
phloem, their abundance increasing
centrifugally.
The conducting phloem is about 1.2-1.8 rom
Sieve cells are rectangular ln TS (Fig. 43D), becoming
collapsed in the radial direction ln the non-conducting
phloem.
«
4
~m
cells.
Minute variously-shaped prismatic crystals
long), are found in the radial walls of s
Their lumina seem to be free of crystals.
areas are about 4-11
wal
single file
~m
in diameter, mostly on
(Fig. 43E).
S
61
Axial parenchyma cells are round to rectangular in
TS (Fig. 43D), and are sometimes difficult to distinguish
from sieve cells in areas near the vascular cambium.
In
al parenchyma cells appear rectangular.
RLS and TLS,
They do not possess tannin contents.
cells in certain short radial fi
Some axial parenchyma
s divide a few times
and expand markedly, becoming rather isodiametric in all
planes (Fig. 43A,B, 44A).
Centrifugally, other parenchyma
cells between the initial
les eventually expand too.
Some axial parenchyma cells, especially some among the
expanding ones develop into sclereids, growing a few times
the size of the original cells, with isodiametric to elongated
shapes.
crys
A few minute variously-shaped
s
«
4
~m
smatic
long) are found in the radi
wall of
axial parenchyma cells.
Phloem rays are uniseriate, occasionally
biseriate and are 1 18
cel~hig
part~
(up to 27 counted).
They
appear round in TLS (Fig. 44B) and rectangular in TS and
TLS.
Eventually some rays expand many times and divide,
becoming rather isodiametric in all planes (Fig. 43A,B, 44B).
These are usually associated with the radial files of
expanding axial parenchyma cells as described above.
Some
15 develop into sclereids, growing a few to many
ray
times the size of the original cells with rather isodiametric
shapes.
Such sc
ified ray cells are usually associated
with the expanded ray cells.
Fibres appear rectangular to almost square in TS
(Fig. 43D), having elongated form with pointed ends.
Their
wall is thick; lignified and birefringent and is made up of
2 main lamellae:
one thin to very thin lamel
on the
outside and one thick lamella on the inside (Fig. 44C).
62
The lumina is small to almost indistinct.
variously-shaped prismatic crystals «
located in the wall of
4
Minute
~m
long) are
bres in the region of the
middle lamella, and are especial
abundant in
radial wall.
Phloem sclereids are developed from some ray and
axial parenchyma cells in the non-conducting phloem,
growing a few to many times the size of the original cells
with isodiametric to elongated (in the longitudinal
direction) shape (Fig. 44D).
They are distributed at
random, very sparse to sparse in number (Fig. 43A-B) .
Their wall is polylamellate, lignified and birefringent.
Most sclereids possess sma
to indistinct lumina.
However,
some sclereids have walls of a few lamellae and large empty
lumina.
In all the specimens studied, the primary cortex was
present.
It seems then that the primary cortex persists
for a long time on the stem.
Cortical cells are rectangular
or oval (oriented in the tangential horizontal direction)
to isodiametric in TS and TLS and isodiametric in RLS.
They do not possess tannin contents.
prismatic crystals
«
30
~m
Variously-shaped
long) are found in the lumina
of a few cortical cells but are found in abundance in the
intercellular spaces (Fig. 44E), the concentration especially
high under lenticels.
Some cortical cells develop into
sclereids at random (sometimes in groups) either with thin
walls (of a few lamellae) and large empty lumina or thick
polylamellate walls with smaller or almost indistinct
lumina (Fig. 44F), remaining about the same shape as the
original cells, growing a few to many times.
both sclereid types are ligni
The walls of
ed and birefringent.
63
Occasional lysigenous-type resin canals of diameter
220-675
~m
are observed mainly in the tangential
horizontal direction, sometimes in the tangential oblique
direction, appearing round to oval in RLS.
The periderm consists of about 30-55 layers of
phellem, one layer of phellogen and about 10 20 layers of
phelloderm. Phelloderm cel
rectangular to square in TS;
are narrowly rectangular or
rectangular to isodiametric
in RLS (Fig. 45A) and narrowly rectangu
(Fig. 44G) to
4-6 sided (Fig. 44H), sometimes isodiametric in TLS.
Cells
in the first few layers closest to the phellogen are often
thin-walled but they eventually develop thickened, nonlignified, slightly birefringent walls.
cells are fill
Some phelloderm
with tannin (Fig. 44H). Some at random
develop into sclereids, growing very little or a few times
but remaining about the same shape as the original cells
(Fig. 44G, 45A) , mostly with distinct lumina and sometimes
filled with tannin.
crystals (mostly < 5
~m
Minute variously-shaped prismatic
long) are found in the wall of
phelloderm cells (Fig. 45B), and are very abundant under
lenticels.
Phellem cells are narrowly rectangular In TS
and RLS and 4-6 sided in TLS.
(Fig. 45C) and mostly fil
They are thin-walled
with tannin contents.
Some
phellem cells, especially the inner layers, have birefringent
cell walls.
Fig. 43
trichomanoides
bark
A.-C.
General view of the living bark
TS(U1) x 60;
this specimen was broken
at
vascular cambium (Vc) at the
bottom of
g.43A; tangential rows of
axial parenchyma cells (P) with 1-2
rows of sieve cells on either side
and tangential rows of fibres (F);
rays (r-r') i
expanded divided ray
and axi
(E) i
sclereids
(Sc),
associated with expanded
parenchyma, very sparse to sparse
in number;
sclereids (Q) i
primary cortex (pc); phelloderm
(pd) i phellem (pm).
The unlabelled
arrow in Fig. 43A
approximately
extent
the
conducting phloem.
D.
General arrangement
cells near the vascu
urn TS(LM) x 625;
rows
al
parenchyma cel
(p) with 1-2 rows
of sieve cells (s) s
by a
row of fibres (f); some
ations
can be seen, e.g. the
(arrowed)
replacing an axial parenchyma celli
ray (r-r l ) . Note the
ar
shape of sieve cells, round to
rectangular shape of axial parenchyma
cells and rectangular to almost
square shape of fibres.
E.
Sieve areas in single file - RLS(SEM)
x 2 625. The top sieve area
s a
vertical and horizontal diameter of
ca. 8 and 10 ~m
respectively whi
those of the bottom sieve area are
ca. 8 and 8 ~m
respectively.
Fig. 43
Fig. 44
Phyllocladustrichomanoides
A.
Expanding and dividing axial parenchyma
cells (E), becoming rather isodiametric
- RLS(LM) x 160; normal axial
parenchyma cells (p).
B.
Expanding and dividing ray parenchyma
cells (E) and a sclereid (Sc) developed
from a ray cell - TLS(LM) x 160;
fibres (f);
note the round shape of
normal ray cells (R).
C.
A fibre, showing the 2 main lamellae of
the wall: one thin lamella on the outside
(1) and one thick lamella on the inside
(2) - TS (SEM) x 2 925.
D.
A macerated phloem sclereid, showing its
elongated shape - (LM) x 60.
E.
Variously-shaped prismatic crystals
(arrowed) in the intercellular spaces of
cortical cells - TS(SEM) x 1 150.
F.
Cortical sclereids, with thin walls of
a few lamellae and large empty lumina
(L) and with thick polylamellate walls
and small or almost indistinct lumina
(Q) - RLS(LM) x 160; note the isodiametric
shape of normal cortical cells (n).
G.
Phelloderm cells, showing their narrowly
rectangular shape - TLS(LM) x 160.
Note some sclerified cells (Sc) growing
very little and remaining the same shape
as the original cell.
H.
Phelloderm cells that appear 4-6 sided
in shape - TLS(LM) x 310. Note some
cells filled with tannin contents.
bark
Fig. 45
Fig. 45
Phyllocladus trichomanoides
A.
Phelloderm cells and a sclereid (Sc)
developed from a phelloderm
1RLS(SEM} x 1 050; note the
isodiametric shape of the cells.
Two other cells (y) are in the
initi
stages of sclerification.
B.
Wall of phelloderm cells, showing
the minute crystals (arrm'led) in
the wall - RLS(SEM} x 2 625.
c.
Phellem cells, showing the thin
'\,valls - RLS(SEl''l} x 2 625. The
arrow at the bottom right points
to the outside of the stem.
bark
64
DISCUSSION
Sieve cells in Agathis australis, Dacrydium kirkii,
Dacrydium biforme, Dacrydium bidwillii, Dacrydium laxifolium,
and Phyllocladus
Dacrydium intermedium, Dacrydium colensoi
possess small to large crys
alpinus
s
(>
8 lJ.ITl long)
in their lumina (scanty in Phy. alpinus) , but crystals
are absent in sieve cells of Libocedrus bidwillii,
Dacrydium cupressinum, Phyllocladus glaucus
L. plumosa,
and Phy. trichomanoides.
Crystals have been reported in sieve cells previously.
Chang (1954b) found them in Pinus elliottii Englem., but
Esau (1969) questioned the observation, suggesting that
it was a mistaken interpretation of crystalliferous
parenchyma cel
as sieve
Is.
Howard (1971) also
noted the same phenomenon in the barks of U.S. southern
pines, including P. elliottii.
In both cases, the crystals
were reported to be styloid in shape.
In the present work,
the crystals are mostly hexagonal prismatic in shape.
Small to large crystals
(>
5
~m
long) also occur in
the lumina of axial phloem parenchyma cells in Agathis
and
australis, Dacrydium biforme, D. bidwillii, Phyllocladus alpinus
Phy. glaucus
(though few in the last two species).
occurrence of crystals in the axi
common in many spec
Bamber 1962;
1977;
Barnett 1974b;
Chan 1979).
species.
phloem parenchyma
(Strasburger 1891;
Srivastava 1963a,bi
Patel 1975;
lS
Chang 1954a,bi
Esau 1969;
Howard 1971,
Bramhall & Kellogg 1979;
Crystal shapes and sizes seem to vary with
In the present work, the crystals in the axi
phloem parenchyma of Agathis australis,
D. bidwillii
The
D. biforme
and
are predominantly hexagonal prismatic in shape
65
but are variously-shaped prisms in Phyllocla.dus a.lpinus
and Phy. gla.ucus.
Minute to small crystals
wall (mainly radi
«
8
~m
long) occur in the
wall) of sieve cells in Libocedrus
bidwillii, L. Plumosa., Da.crydium bidwillii, D. la.xifolium,
D. cupressinum, D. intermedium, D. colensoi, Phyllocla.dus a.lpinus,
Phy. gla.ucus and Phy.trichoma.noides, but are absent in the wall
of sieve cells in
D.
biforme.
and
Aga.this a.ustra.lis, Da.crydium kirkii
They also occur in the radial wall ofaxi
parenchyma cells in Libocedrus bidwillii, L.
umosa., Da.crydium
kirkii, D. la.xifolium, D. cuppressinum, D. intermedium, Phyllocla.dus
, Phy. gla.ucus
and
Phy. tri choma.noi des ,
but not
ln
wall of axial parenchyma cells in Aga.this a.ustra.lis, Da.crydium
biforme, D. bidwillii
and
D.
colensoi.
Various researchers have
mentioned the occurrence of such minute crys
s
(sometimes
referred to as 'crystal sands') in the wall of phloem cells
(Strasburger 1891;
Chan 1979;
1980).
Chang 1954a;
Bamber 1959;
Parameswaran & Liese 1979;
Esau 1969;
Franceschi & Horner
Strasburger (1891), Chang (1954a), Bamber (1959)
and Chan (1979) have specifically indicated that the
cry
s occur only in
radial wall in some species.
Esau (1969) suggested that the
primary wall and subsequent
pockets in the secondary wall.
tals are formed in the
become embedded in
1
Later, the pockets of
stals are pushed outwards by normal growth with the
consequence that
cellular spaces.
crystals become located in the interEsau (1969) also pointed out that this
phenomenon appears to
Da.crydium cupressinum
less common in angiosperms.
is the only spec
s among the
New Zealand gymnosperms where Land T-shaped phloem
parenchyma have been observed.
The course of development
66
of such cells is unknown;
neither is their function.
Such cells have never been reported anywhere in the
literature previously.
Another interesting feature in D. cupressinum is the
occurrence of some axial phloem parenchyma cells with
corrugated radial wall, a feature which is not found in
any other species of New Zealand gymnosperms.
Neither
has it been reported elsewhere.
Yet another feature confined to D. cupressinum
is the
presence of some long axial phloem parenchyma cells whose
mother cells did not undergo transverse divisions.
Esau
(1969) refeJ?red to such cells as fusiform parenchyma cells
and those with transverse divisions as parenchyma strands.
Zahur (1959), however, used the terms 'cambiform cells'
and 'strand-forming parenchyma cells' respectively.
When the axial parenchyma mother cells divide in the
proximity of the vascular cambium in
D. biforme
Agathis australis,
and D. cupressinum, some cells form walls in the
radial longitudinal plane and
so in the transverse
plane, giving two strands of parenchyma cells that are
ontogenetically related.
Sometimes the transverse wall
is laid down obliquely, giving
parenchyma.
se to abnormally-shaped
This phenomenon has not been observed in the
other species of New Zealand gymnosperms.
Libocedrus bidwillii, L. plumosa, Dacrydium bidwillii,
D. laxifolium
10 cells
and D. colensoi have phloem rays of up to about
height i
Agathis australis, Dacrydium kirkii,
D. biforme, D. intermedium, Phyllocladus alpinus, Phy. glaucus and
Phy. trichomanoides
high, while
have phloem rays of up to about 20 cells
Dacrydium cupressinum
30 cells high.
have phloem rays of up to
Minute to small crystals «
8
~m
long) are
67
found in the inter-cellular spaces between ray and
longi tudinal cells in
Dacrydium laxifolium, D. cupressinum and
This phenomenon had also been observed in
D. colensoi.
and P. totara var.
Podocarpus dacrydioides, P. spicatus
(Chan 1979).
c
waihoensis
Esau's (1969) explanation, given above, for
tals in the wall of sieve and axial phloem parenchyma
cells may equally apply here.
The fibres of Agathis australis, Dacrydium species and
Phyllocladus
spec
all possess thick walls with small to
indistinct lumina.
However, the fibres of
Libocedrus species
are of two types, thin-walled with rather large and distinct
lumina and thick-walled with small to almost indistinct
lumina.
The phloem fibres of all species except Agathis
australis have lignifi
whi
walls made up of two main lamellae,
the phloem fibres of Agathis australis are mostly non-
lignified and are made up of three main lamellae.
of all species are birefringent.
f
Fibres
with the exception of
s in Libocedrus phloem, phloem
bres of all other
species have an elongated form with pointed ends.
In
the phloem fibres are elongated, appearing
Libocedrus,
pointed in TLS, but often with rather abrupt or blunt
ends when viewed in RLS.
Minute to small crystals
wall (in the region
Phyllocladus
Libocedrus
8
~m
long) occur in the
the middle lamella) of fibres in
both species of Libocedrus
Phyllocladus.
«
and in
three species of
They are most abundant in the radial wall in
species but occur only in the radial wall in
spec£es.
The presence of crystals in the wall
of phloem fibres was probably first reported by Moeller
(1882) in Taxus.
the phloem fibre
calirornica
Torr.
Chang (1954a) subsequently found them
1 in Taxus brevifolia Nutt., and Torreya
68
Phloem sclereids are absent in Libocedrus species and
are rare in
Dacrydium laxifolium.They are very sparse to
sparse in Phyllocladus glaucus and Phy. trichomanoides,
in Dacrydium biforme and
in
D. colensoi,
Phy. alpinus,
sparse
sparse to moderate
sparse to abundant in D. intermedium,
moderate
to abundant in D. bidwillii, abundant in D. kirkii and very
abundant in. Agathis australis andD . .cupressinum.
In the phloem
of D. intermedium, . the large sclereids possess large lumina
while the small sclereids possess small to almost indi
lumina;
nct
most of the phloem sclereids inA. australis have
large empty lumina. phloem sclereids in Phyllocladus and
Dacrydium
(apart fromD. intermedium)
almost indistinct lumina.
ies have small to
The walls of the sclereids in
all species are polylamellate (sometimes some sclereids
with wall of a few lamellae), lignifi
and
fringent.
Albuminous or Strasburger cells occur as erect or
upright cells along
margins of phloem rays in species
whose wood possess ray tracheids along the margins of
xylem
(Howard 1971).
Such albuminous cells have been
described by Chang (1954a,b), Esau (1969) and Howard (1971).
Patel (l967a,b, 1968a,b) made no mention of ray tracheids
in the ray of woods of New Zealand gymnosperms.
& Butterfield (1978)
Meylan
stated that ray tracheids are absent
in the wood of Agathis australis, Libocedrus bidwillii,
L. plumosa,
Dacrydium biforme, D. colensoi, D. cupressinum, D. kirkii, Phyllocladus
alpinus, Phy. glaucus
and
Phy. trichomanoides.
Upright or erect
cells along the margin of rays have not been seen in the
phloem of the species studied.
However, that does not mean
that albuminous cells are absent.
reported to be
tissues (Chang 1954b;
Albuminous cells have
stributed among
Sr
tava 1963b;
other phloem
Esau 1965).
69
According to Evert (1977), the principal feature
distinguishing albuminous cells from other phloem
parenchymatous cells is their connections with sieve
cells:
pores on the sieve cell side and branched
plasmodesmata on the albuminous cell side.
Such a
feature can only be confirmed by transmission electron
microscopy, hence a description of albuminous cells in
this work is not included, since their presence or
absence was not fully certain.
Chan (1979) mentioned
the presence of upright or erect albuminous cells along
the margins of phloem rays in some species of New Zealand
Podocarpus,
but it is questionable whether those cells were
in fact albuminous cells or ordinary ray cel
that
appeared slightly upright.
Trabeculae seem to be a very common feature in the
phloem of Libocedrus bidwillii observed.
Neither Patel
(1968b) nor Meylan & Butterfield (1978) have mentioned
the occurrence of trabeculae in the wood of
bidwillii.
Libocedrus
The three trees in this present work were
from the same geographical area in a valley.
Trabeculae
are believed to originate in the vascular cambium where
the cell wall material is deposited about a fine filament
Muler~Sto
which presumably traverses the living cell (Keith 1971).
(
65), however, suggested that frosts may
induce the formation of trabeculae.
Butterf
ld & Meylan
(1980) suggested that trabeculae result from periclinal
divisions in cambial initials or xylem mother cells such
that the cell plate fus
with a side wall at some point,
producing a rod upon radial expansion.
abundant trabeculae in Libocedrus bidwillii
present work is uncertain.
The reason for
phloem in this
However, Muller-Stoll's (1965)
70
frost hypothesis may apply since the trees were collected
from a valley.
Fungal hyphae were not observed at all
in any of the specimens and hence they were not likely
to be the cause of trabeculae formation.
The suggestion
of Butterfield & Meylan (1980) is also plausible and may
genetically related.
The primary cortex
noted to persist on the stem
for a long time in Agathis australis, Dacrydium kirkii, D. biforme,
D. bidwillii, D. laxifolium, D. colensoi
spec
The persistence of the primary
s of Phyllocladus.
cortex on the stem of
and all the three
D. kirkii, D. colensoi and all three
species of Phyllocladus has been recorded by Craddock (1932a).
Derivatives (i.e. phellem and phelloderm cells) of
the phellogen developed from primary cortical cells mostly
appear elongated to rectangular in TLS, with their long
axes in the tangential horizontal direction as distinct
from those derivatives of the phellogen developed from
phloem parenchyma cells, which mostly appear 4-6 sided in
TLS.
Phellem cells in
flimsy walls.
Libocedrus species have very thin
In Agathis australis,
phellem are thin-
walled, sometimes with the inner tangential wall slightly
thicker than the outer tangential wall.
In older stems
(where phellogen is derived from phloem parenchyma)
I
the
outer 1-3 layers are thick-walled and larger in size than
the inner phellem cells.
cupressinum
Phellem cells in Dacrydium
have thin walls.
In all the other six Dacrydium
species, the phellem cells are mostly thin-walled but some
possess an inner tangential wall that is thicker than the
outer tangential wall.
In
Dacrydium kirkii, D. biforme
D. bidwillii, this thicker inner tangential wall is se
and
f
71
while in
D. laxifolium, D. intermedium
and
D. colensoi,
this wall is non-polylamellate and possess cone-shaped
structures which protrude into the lumen.
This latter
feature is also shared by some phellem cells in Phyllocladus
alpinus but most of the phellem cells in Phy. alpinus
all of the phellem cells in
are thin-walled.
Phy. glaucus
and
and Phy. trichomanoides
The phenomenon of a thicker inner
tangential wall (whether sclerified or otherwise) has not
been reported before, though it is known that in Pinus
spec
s, some phellem cells have thick sclerified wall
with even thicknesses all round (Chang 1954a,bi
1971;
Howard
Patel 1975).
In terms of the number of layers of phellem cells,
six groups can be identified.
only 2-3 layers i
4 11 layers;
Libocedrus
species have
Dacrydium laxifolium and D. intermedium
D. biforme
have
(in old stems where phellogen is
derived from phloem parenchyma,) D. bidwillii and Phyllocladus
alpinus
have 5-30 layers;
D. biforme
(in young sterns where
phellogen is derived from cortical cells) and
have 25-45 layers;
Agathis australis, D. kirJdi, D. cuppressinum
and Phy. trichomanoides
has 80-150 layers.
D. colensoi
have 30-70 layers, and Phy. glaucus
On the other hand, Craddock (1932a)
observed up to 110 layers of phellem in D. cupressinum,
60-70 layers in
D. colensoi
and 40-50 layers in Phy. alpinus.
He did not study the other species in detail and thus did
not mention the number of layers found.
In a number of species, phelloderm is made up of
two types of cells, namely, normal thin-walled cells and
scleri
ed phelloderm cells.
A few of the phelloderm cells
develop into sclereids in Dacrydium intermedium, Phyllocladus
alpinus and Phy. glaucus;
some phelloderm cells develop into
72
sclereids in
D.
Agathis australis,
kirkii,
D.
and Phy. trichomanoides;
colensoi
phelloderrn cells in
D.
D.
biforme,
and a number of
cupressinum develop into sclereids.
None of the phelloderm cells in Libocedrus bidwillii,
D.
bidwillii
and
D.
However I all of
laxifolium develop into sc
reids.
phelloderm cells in Libocedrus plumosa
develop into sclereids just prior to death, when a new
phellogen is developing further inside the phloem.
number of layers of phelloderm cells,
Based on
four groups can be identified.
Libocedrus bidwillii,
and Dacrydium laxifolium
L.
plumosa
D.
bidwillii,
D.
3-10 layers i
Phy. glaucus
intermedium
D.
have 2-4 1
s;
and Phyllocladus alpinus
have
kirkii, D. biforme, D. cupressinum, D. colensoi,
and Phy. trichomanoides have 6-20 layers, while
Agathis australis
has 25-35 1
found 12-14
However, Craddock (1932a)
s of phelloderm cells in
D.
cupressinum,
10 of which were thick-walled (probably meaning sclerified).
He reported 3-4 1
Again, since
rs in both
D.
colensoi and Phy.
did not study the other species in detail,
the number of layers of phelloderm in those species was
not mentioned.
In the two Libocedrus species, there are differences
between the shapes and
phelloderm) of the
zes of derivatives (phe1lem and
llogen cells developed from ray cells
and the shape and sizes of those from ax±a1 parenchyma
cells.
cells
Phel
and phelloderm cells produced by phellogen
loped from axial parenchyma cells are 4-6 sided
in shape in TLS while those from ray cells are rather
isodiametric and smaller in size.
Such differences between
derivatives of phellogen developed from ray cells and those
from axial parenchyma cells do not exist in other
of gymnosperms.
s
73
Lenticels were not observed in the two Libocedrus
species, nor in Dacrydium laxifolium.
in all other species.
D. bidwillii,
In
They were present
and
D. kirkii, D. biforme
minute crystals occur in the wall of phelloderm
cells only under lenticels.
In Agathis australis, D. intermedium,
D. colensoi, Phyllocladus alpinus, Phy. glaucus and Phy. trichomanoides,
some crystals occur in the wall of phelloderm cells throughout but are most abundant under lenticels.
In
D. cupressinum,
crystals in the wall of phelloderm cells seem to occur
throughout, irrespective of lenticels.
Though lenticels
were not observed in D. laxifolium, some minute crystals were
noted in the wall of some phelloderm cells.
Crystals
were, however, not observed at all in the wall of phelloderm
cells of Libocedrus species.
The occurrence of crystals
only under lenticels or the greater abundance of crystals
under lenticels have not been reported before.
This
feature may indicate that formation of crystals is related
to gaseous exchange, which is believed to be the function
of lenticels (Cutter 1969).
Phloem resin canals are found only in Agathis australis.
Resin canals are also found in the primary cortex of
Agathis australis
and all the three species of Phyllocladus
and in the phelloderm of A.australis. They all seem to be
formed lysigenously.
A. australis
Only those in the phelloderm of
seem to readily form anastomoses.
The resinous
nature of the bark of A. australis is well known.
Hinds
&
Reid (1957) mentioned that in mature trees, the massive
branches are impregnated with resin and also that other
inflammable organic material collect at the base of the
trunk together with large mounds of shed bark.
they made no mention of any re
in the bark of
However,
Phyllocladus
74
Moeller (1882) reported the presence of
trichomanoides.
resin cavities
trichomanoides.
(~
Harzraume) in the cortex of Phy.
Craddock (1932a) described resin canals
in the primary cortex of Phy. alpinus as very numerous,
"often only one or two layers of cortical cells separating
one canal from another",
He seems to have observed them
only in the axial direction.
Kucera & Butterfield (1977)
found that resin canals occur regularly in the cortex of
the three New Zealand species of
Phyllocladus,
and that they
arise following a schizogenous developmental pattern.
They
also observed that the resin canals follow different
courses, varying from straight vertical, vertical/radially
inclined, vertical/tangential inclined, horizontal/radial
and horizontal/tangential to circumferential but that no
definite anastomoses were observed.
In the present work,
cortical resin canals were found to be occasional and occur
mainly in the tangential horizontal direction in Phy.
trichomanoides,
and only in the tangential horizontal
direction in the other two species.
The only other species
of New Zealand gymnosperms that possess phloem resin canals
is
Podocarpus ferrugineus
(Hinds
&
Reid 1957 i
Chan 1979),
Chan (1979) has also reported the presence of spherical
cavi ties in the phelloderm of
P. spicatus
which he thought
could be secretory in nature.
Based on the present work and the work of Chan (1979),
the following key using minimal bark features to separate
the species
A.
New Zealand gymnosperms is proposed:
Resin canals present in phloem
B.
Resin canals also in phellodermi
fibres
mostly not lignified;
sclereids mostly
wi th large empty lumina . . . . . . . . . . . . . . . A. australis
75
BB. Resin canals not present in phelloderm;
sclerotic phloem fibres, together with
fibres and sclereids present in
phloem .....•.•.......•.........•.•.. P. ferrugineus
AA.
Resin canals absent in the phloem, but
present in the primary cortex; marked
expansion and division of ray and axial
parenchyma cells
certain radial files;
sclereids very sparse to sparse
B.
Outer layers of phellem cells thinwalled; inner layers have thicker
inner tangential wall with coneshaped structures protruding into
lumina ....•.........•...•........... Phy. alpinus
BB. Phellem cells all thin-walled
C.
Phellem consisting of 30 70
layers •......................... Phy. trichomanoides
CC.Phellem consisting of 80-150
1
MAo
........•......
0
•
•
•
•
•
•
••
Phy. glaucus
Resin canals not present in any bark
tissue
B.
Phloem sclerenchyma rare or absent ..• D. laxifolium
BB. Phloem s
only .•
0
erenchyma of sclereids
•••
0
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
••
P. spicatus
BBB.Phloem sclerenchyma of fibres
only
C.
F
s of two types:
and thick-wal
D.
thin
Thick-walled f
scattered;
phelloderm cells appear
co apsed in
rhytidome .. L. bidwillii
DD. Thick-wal
fibres mostly
in tangential rows;
phelloderm cells
lop
into sclereids just prior
to death, thus not
collapsing in the
rhytidome. . . .. .. .. .. . . . . ...
CC.
Fibres of one type:
D.
L.
plumosa
thick-walled
Rays up to 22 cells high...
DDo Rays up to 6 cells high
to tara var
waihoensis
P.
76
E.
Series of cell type in
a radial row following
sequence:
parenchymasieve cell-sieve cellfibre-sieve cell-, from
inside going outwards;
each cell type generally
in tangential rows ......
EE. Series of cell types in
a radial row following
sequence: parenchymasieve cell-sieve cellparenchyma-sieve cellfibre-sieve cell-, from
inside going outwards;
each cell type generally
in tangential rows.....
P.
hallii
P. nivalis
EEE.Series of cell types in
a radial row following
sequence: parenchymasieve cell- fibresieve cell-, from inside
going outwards; each
cell type generally in
tangential rows ...... P. acutifolius
BBBB. Phloem sclerenchyma of both sclereids
and fibres
C.
Fibres mostly narrowly rectangular
In TS
D.
Rays up to 20 cells high ...
P. dacrydioides
DO. Rays up to 30 cells high;
Land T-shaped parenchyma
common . . . . . . . . . . . . . . . . . . . . . . D. cupressinum
CC. Fibres rectangular to narrowly
rectangular in TS
D.
Phellem cells mostly thinwalled;
some with thicker
sclerified inner tangential
wall
E.
phloem cells without
any regularity of pattern;
living bark thickness up
to 2.00 mm;
sclereids
moderate to abundant in
number. . . . . . . . . . . • . . . . .. D. bidwillii
77
EE. rhloem consisting of long
or short tangential rows,
sometimes individual cells,
of axial parenchyma cells
separated by about 2-5 rows
of
eve cells and fibres
scattered at random among
each other;
living bark
thickness over 3.00 mm
F. Sc
ids abundant .....
D.
kirkii
FF. Sclereids sparse.......
D.
biforme
DD. Phellem cells mostly thinwalled; some with thi
non-scleri
inner
tangential wall, mostly
without contents;
coneshaped structures protruding from inner tangential
wall into lumina ......•.•.... D. colensoi
DDD.Phellem cells mostly with
thicker non-sclerified
inner tangential wall with
cone shaped structures
protruding into the lumina;
mostly fil
wi th tannin ...
The three Phyllocladus
anatomical
D.
intermedium
species have very small bark
fferences between them.
Although, in the
above key, phellem morphology and number of layers of
phellem have been employed to distinguish between Phy.
glaucus
and
Phy. trichomanoides,
the author does not feel
fully confident about the use of these features to separate
the species beyond any doubt.
very small wood anatomi
Patel (1968a) also found
differences between
three
species of Phyllocladus.
Confirmation of the above key for identification
of specimens encompassing a wider geographical origin is
needed.
78
ACKNOWLEDGEMENT
The author wishes to express his thanks to the
llowing:
(1)
Prof. E.L. Ellis for supervising the work,
his advice and encouragement,
(2)
Dr. B.G. Butterfield for his encouragement, as
assistant supervisor,
(3)
Dr. B.A. Fineran for his advice and
(4)
Mrs. K. Card for her assistance in the scanning
electron microscope work, and
cially
patience and dedication as I
(5)
her
technician,
New Zealand Forest Service and Arthur's Pass
National Park for permission to col
the
specimens,
(6)
Mrs. G. Lamb for typing the work,
(7)
Mr. K. Schasching for his assistance and advice
in the laboratory work,
(8)
Mr. P. Nieuwland
his assistance in the
collection of some of the specimens,
(9)
All those who have assisted in one way or other,
however small, in the course of the work.
79
REFERENCES
LITERATURE CITED
Allan, H.H.
(1961)
Flora of New Zealand, Vol. I.
Government Printer, Wellington, NeZ. pp.104-115.
Bamber, R.K.
(1959)
Anatomy
species of Callitris Vent.
84: 375-381.
the barks of five
Linnean Soc. N.S.W.
The anatomy of the barks of
Australian Journal Botany 10:25-54.
Bamber, R.K.
(1962)
Leptospermoideae.
Barnett, J.R.
(1974a)
Secondary phloem in Pinus
radiata D. Don 1.
Structure of differentiating
sieve cells. N.Z.J. of Bot. 12:245-260.
Barnett, JeR.
(1974b)
Secondary phloem in pinus
radiata D. Don 2.
Structure of parenchyma cells.
N.Z.J. of Bot. 12:26 274.
Bramhall, A.E. & R.M.
logg
(1979)
Anatomy of
secondary phloem of western hemlock,
Tsuga
(Raf.)
Sarge
I.A.W.A. Bulletin 1979/4:79-85.
Butterfield, B.G. & B.A. Meylan
(1980)
Three
dimensional structure of wood.
2nd ed.
Chapman
& Hall, London, New York.
Chan, L.L.
(1979)
anatomy of New Zealand
Christchurch, University of
(Dissertation: B.For.Sc.)
es.
Podocarpus
Canterbury.
13
Chang, Y.P.
conifers.
(1954a)
Bark structure of North
U.S.D.A. Tech. Bulletin No. 1095.
Chang, YeP.
pulpwood
(1954b)
Anatomy of common North
can
TAPPI Monograph Series No. 14.
Chattaway, M.M.
(1953)
The genus Eucal
Chattaway, M.M.
Oil
Bot. 3:21-27.
The anatomy of bark I.
Australian J. of Bot. 1:402-433.
(1955a)
Eucalyptus
The anatomy of bark II.
species. Aus
ian J. of
Chattaway, M.M.
(1955b)
The anatomy of bark III.
Enlarged fibres in the bloodwoods (Eucal
species) •
Australian J. of Bot. 3:28-38.
Chattaway, M.M.
(1955c)
The anatomy of bark IV.
Radi ly elongated cells in the phell
of
spec
of Eucalyptus.
Australian J. of Bot. 3: 39 47.
Chattaway, M~.
(1955d)
The anatomy of
V. Eucalyptus species wi th stringy bark.
Aus
ian J. of Bot. 3:165-169.
Hi E lIlHI.Alrf
UNIVERSITY OF CANTEIUIURY
CHRISTCHURCH. N.l.
80
Chattaway, M.M.
(1955e)
The anatomy of bark
VI. Peppermints, boxes, ironbarks and other
eucalypts with cracked and furrowed barks.
Australian J. of Bot. 3:170 176.
Chattaway, M.M.
(1959)
The anatomy of bark
VII. Spec s of Eugenia (sens. lat.).
Trop. Woods 111:1-14.
Craddock, o.
(1932a) The rind of the Podocarps
with speci
reference to the bark. Canterbury
College, University of New Zealand, Christchurch.
84p.
(Thesis: M.A.: Botany).
Craddock, O.
(1932b)
The rind of the Podocarps
with special reference to the bark. Te Kura
Ngahere (J. of the N.Z.Sch.
Forestry) 111(2):
61-65.
Crist, J.B.
(1972) Periderm morphology and thick
walled phellem ultrastructure
long leaf pine
(Pinus palustris MilL).
Virginia Polytechnic Institute
and State University. l43p.
(Ph.D. thesis).
Cutter, E.G.
(1969)
Plant anatomy: Experiment and
interpretation; Part I - Cells and tissues.
Edward Arnold Publishers Ltd, l68p.
Datta, S.K.
(1981)
Bark anatomy of important laticiferous
woody plants. I.A.W.A. 50th anniversary sympos
XIII International Botanical Congress, Sydney,
(Aug. 24-28).
{To be published: In Baas, P. (Ed) (1982)
New perspectives in wood anatomy.
(See I.A.W.A.
Bulletin (new ser s) 2(2 & 3): 56 57)}
De Laubenfels, D.J.
(1969) A revision of the Malesia
and Pacific rain forest conifers I. Podocarpaceae.
Arnold Arboretum J. 50:274-369.
Den Outer, R. W.
(1967)
Histological investigations of
secondary phloem of gymnosperms.
lingen
Landbouwhogeschool Wageningen, Nederland 67:1-119.
Esau, K.
(1934)
vulgaris
Ontogeny of phloem in the sugar beet
L.). American J. Bot. 21:632-644.
Esau, K.
(1938)
Ontogeny and structure of
of tobacco. Hilgardia 11:343-424.
phloem
Esau, K.
(1968)
Plastids and mitochondria
the
phloem of Cucurbita.
Canadian J. of Bot. 46: 877-880.
Esau, K.
(1969)
The phloem. Handbuch der
lanzenanatomie
(Encyclopedia of plant anatomy) series. Gebruder
Borntraeger, Berlin. 50
(1962)
Esau, K., V.I. Cheadle and E.B. Risley
pores. Bot. Gaz.
Development of sieve-p
123:233-243.
81
Evert, R.F.
(1960)
Phloem structure in Pyrus communis L.
and its seasonal changes. Un. Ca f. Publ. Bot.
32:127-194.
Evert, R.F.
(1963a) Ontogeny and structure of the
secondary phloem in pyrus malus.
American J. of
Bot. 50:8-37.
Evert, R.F.
(1963b) Sclerified companion cells in
Bot. Gaz. 124:262 264.
Tilia americana.
Evert, R.F.
(1977)
Phloem structure and histochemistry.
Ann. Rev. Plant Physiol. (1977) 28:199-222.
Exley, R.R." B.G. Butterfield & B.A. Heylan
(1974)
Preparation of wood specimens for the scanning
electron microscope. J. of Microscopy 101(1):
21-30.
Exley, R.R., B.A. Meylan & B.G. Butterfield
(1977)
A technique for obtaining clean cut sur
on
wood samples prepared for the scanning electron
microscope. J. of Microscopy 110(1) :75 78.
Franceschi, V.R. & H.T. Horner, Jr.
(1980)
Ca ium oxalate crystals in plants. Botanical
Review 46:361-427.
Goldschmid, O. & M.W. Folsom (1975)
A note on the
appearance of sclere
from western hemlock inner
bark. Wood and Fiber 7:146-148.
Hinds, H.V. & J.S. Reid
(1957) Forest trees and timbers
of New Zealand. New Zealand Forest Service Bulletin
No. 12. 211p.
Howard, E.T.
(1971) Bark structure of the southern
pines. Wood Science 3(3):
4-148.
Howard, E.T.
(1977) Bark structure of the southern
upland oaks. Wood and Fiber 9(3) :172-183.
International Association of Wood Anatomists,
Committee on nomenclature (1964) Multilingual
glossary of terms used in wood anatomy.
Verlagsanstalt Buchdruckerei Konkordia Winterthur.
186p.
Keith, C.T.
(1971) Observations on the anatomy and
fine structure of the trabeculae of Sanio.
I.A.W.A. Bulletin 1971/3:3-11.
Kucera, L.J. & B.G. Butterfield (1977)
Resin canals
in the bark of Phylloc1adus spec s indigenous to
New Zealand. N.Z. J. of Bot. 15:657-663.
Litvay, J.D. & R.L. Krahmer
(1976)
The presence of
callose in cork cells. Wood and Fiber 8(3) :146-151.
82
Meylan, B.A. & B.G. Butterfield
(1978)
The structure
of New Zealand woods.
D.S.I.R. Bulletin 222, N.Z.
Department of Scienti c and Industrial Res
Wellington, New Z
and.
t1oeller, J.
447p.
(1882)
Anatomie de Baumrinden.
Berlin.
MUller-Stoll, W.R.
(1965)
Ueber intraz
Stabbildungen
ae) in Holz als
sche
Eigenhart bei Geholzen exponierter Gebregsl
Die Kulturpfl. 13:763-799. Akademie Verlag, Berlin.
(1977)
Development
Nanko, H., H. S
i & H. Harada
phloem fibres in
secondary
and structure of
phloem of Popul us eurarnericana. J. Jap. Wood Res. Soc.
23:267-272.
Parameswaran, N.
sklereiden
85:305-314.
(1975a)
Zur wands
igen Baumrinden.
von
Protoplasma
Parameswaran, N.
(1975b)
Fine structure and lignin
character of sclereids in tree bark. Technical
sessions of I.A.W.A., XII International Botanical
Congress, Leningrad, (July 3-10).
Parameswaran, N.
(1980)
Some
nomenc
of fibres, sclereids
in the
y phloem of trees.
(new s
1 (3) : 130-132.
on the
fibre-sclereids
I.A.W.A. Bulletin
Patel, R.N.
(1967a)
Wood anatomy of Podocarpaceae
indigenous to New Zealand 1.
urn.
N.Z. J. of
Bot. 5:171 184.
Patel, R.N.
(1967b)
Wood anatomy of Podocarpaceae
to New Zealand 2. Podocarpus.
N. Z. J.
Bot. 5:307 321.
Patel, R.N.
(1968a)
Wood
indigenous to New Zealand 3.
of Bot. 6: 3 - 8.
of Podocarpaceae
Phyllocladus.
N. Z.
J.
Patel, R.N.
(l968b)
~vod
of Cupressaceae and
Araucariaceae indigenous to New Zealand.
N.Z. J. of
Bot. 6:9-18. P
,R.N.
(1975)
Bark anatomy of radiata pine,
Corsican pine and Douglas
r grown in New Zeal
N.Z.J. of Bot. 13;149-167.
Purvis, M.J., D.C. ColI rand D. Walls
(1966)
Laboratory techniques in botany.
2nd Ed.
Butterworths, London.
439p.
,H.G.
(1980)
Anatomie des sekundaren
und der rinde der Lauraceae. Fachbereich
Universitat Hamburg.
e,
83
Robinson, D.E. & J.K. Grigor
(1963)
The origin of
periderm in some New Zealand plants. Transactions
of the Royal society of New Zealand (Botany)
2 (9) :121-124.
Schneider, H.
(1945)
The anatomy of peach and cherry
phloem. Bull. Torr. Bot. Cl. 72:137-156.
Shah, J.J. & M.R. James
(1968)
Sieve tube elements
in
stem of Neptunia oleraceae Lour.
Australian J. of Bot. 16(3) :433-444.
Sinz, P.
(1925)
Calciumoxalat-kristal
als
Bausteine im mechanischen system der Cupressineenrinde. Bot. Arch. 10:10-16.
Society of American Foresters
(1958)
Forestry
terminology.
3rd Ed. Society of American Foresters,
Washington D.C.
97p.
(1963a)
Cambium and vascular
Srivastava, L.M.
derivatives of Gingko biloba. Arnold Arboretum
J. 44:165-192.
Srivastava, L.M.
(1963b)
Secondary phloem in the
Pinaceae. U.C.L.A. Publ. Bot. 36:1-142.
Srivastava, L.M.
(1970)
Astrobaileya scandens 0
secondary phloem of
Canadian J. of Bot. 48: 341-3590
Srivastava, L M. & ToP. O'Brien
(1966)
On the
ultrastructure of cambium and its vascular
derivatives II. Secondary phloem of Pinus strobus L.
Protoplasma 61:277-293.
Strasburger, E.
(1891)
Ueber den Bau und
Verrichtungen der Leitungsbahnen in den Pflazen.
stologische Beitrage Heft III. Jena, Gustav
Fischer.
Thomson, R.B. & H.B. Sifton
(1925)
Resin canals in
Canadian spruce (Picea canadensis (Mill.) B. S . P . )
- an anatomical study, especially in relation
to traumatic effects and their bearing on
phylogeny. Royal Society, London, Phil. Trans.
Series B 214:63 11.
Zahur, M.S.
(1959)
Comparative study of secondary
phloem of 423 species of woody dicotyledons
belonging to 85 fami
s.
Agricultural
Experimental Station, Cornell University,
Memoir 358.
84
OTHER LITERATURE CONSULTED
Aronoff S., J. Dainty, P.R. Gorham, L.M. Srivastava
& C.A. Swanson
(1975)
Phloem transport.
Plenum Press, New York. 636p.
Bamber, R.K. & R. Summervil
(1979)
Taxonomic
significance of sclerified tissue in the barks
of Lauraceae.
I.A.W.A. Bulletin 1979/4:69-74.
Cronshaw, J.
(1974)
Phloem differentiation and
development. In Robards, A. W. (Ed. )V197 4)
Dynamic aspects of plant ultrastructu.re.
McGraw-Hill Book Co., (U.K.) Ltd. p~391-4.
Esau, K.
(1965)
Plant anatomy 2nd Ed.
& Sons, Inc. 767p.
John Wi
Jackman, V.H.
(1960)
The shoot apex ot some New
Zealand gymnosperms.
Phytomorphology 10:145-157.
Konar, R.N.
(1969)
podocarpus gracilor.
Anatomical st~die
on
Phytomorphology 19:122-133.
Martin, R.E.
(1969)
Characterization of the southern
pine barks.
Forest Prod. J. 19(8) :23-30.
Martin, R.E. & J .B. Crist
(1970)
Elements of bark
structure and terminology. Wood and Fiber 2(3):
269-279.
Parameswaran, N.
(1979)
A note on the fine structure
of trabeculae in Agathis alba.
LA.W.A. Bulletin
1979/1:17-18.
Singh, A.P.
(1980)
On the structure and differentiation
of the phloem in sugarcane leaves. Cytologia 45:
31.
Werker, E. & P. Baas
(1981)
Trabeculae of Sanio in
secondary tissues of Inula viscosa (L.) Des f .
and Salvia fruiticosa Mill. LA.W.A. Bulletin
(new series) 2(2-3} :69-76.
85
APPENDIX I
PREPARATION OF
(1)
5% GLUTARALDEHYDE IN 0.025 M PHOSPHATE BUFFER
Preparation of stock phosphate buffer solutions:
Solution A:
Dissolve 2.225 g di-sodium hydrogen
orthophosphate (Sorensen's salt,
Na HP0 02H 0), in 500 ml distilled
2
4
2
water.
Solution B:
Dissolve 1.7 g potassium dihydrogen
orthophosphate (KH 2 P0 ) in 500 ml
4
distilled water.
(2)
ion of working solution (pH= 7.2):
Mix in the proportion 8:5 of A:B.
86
APPENDIX II
STAINING SCHEDULE FOR LIGHT MICROSCOPE SECTIONS
(1)
Preparation of stains:
Safranin:
1 g of safranin
solved in 100 cm
3
of
60% alcohol (i.e. 1% safranin solution).
Fast green: 0.5 g of
t green dissolved in 100 cm
3
of solution containing equal parts of
absolute alcohol, clove oil and methyl
cellosolve.
(2)
Staining schedule:
(a) Hand sections are placed on a glass s
in a few
drops of 60% alcohol until staining commences;
(b) The 60% alcohol is rep
by a few drops of
the safranin solution for about 5 minutes;
(c) Sections are then washed in 95% alcohol till no
more safranin comes off the sections;
(d) They are then washed and Ie
in a few drops of
absolute alcohol for about 5 minutes;
(e) The absolute alcohol is replaced by a few drops
of fast green.
stain
(f) A very br
The sections remain in this
about 30 seconds;
f wash with absolute alcohol to
remove excess
t green stain is carried out;
(g) A few drops of clove oil is applied to the
sections
about 1 minute;
(h) The clove oil is washed off with xylol;
(i) Sections are then mounted permanently in a
drops of Permount medium.
87
APPENDIX III
DETAILS OF THE INCREASING CONCENTRATION ALCOHOL SERIES
(1)
Final cuts are made on the block;
(2)
Wash the block in 5% sodium hypochlorite for
about 15 minutes, if required;
(3)
The block is then soaked for at least 5 hours in
each
the following concentrations of alcohol:
15%, 30%, 50%, 70%, 95% and 100%;
(4)
Finally, the block is transferred into 100% amyl
acetate and kept in it for at least 5 hours,
until it is critical point dried.
Lek-Lim Chan