Larix gmelinii var. olgensis

Scientific name: Larix gmelinii var. olgensis (A. Henry) Ostenf. & Syrach  1930

Synonyms: Larix amurensis Kolesn. ex Dylis, Larix gmelinii var. koreana (Nakai) Uyeki, Larix gmelinii subsp. olgensis (A.Henry) A.E.Murray, Larix koreana Nakai, Larix lubarskii Sukaczev, Larix olgensis A.Henry

Common names: Olga Bay larch

Description

Tree to 20(-25) m tall, with trunk to 0.5(-0.8) m in diameter. Bark gray or grayish brown, smooth at first, becoming flaky, and finally breaking up into broad, scaly plates, separated by wide, shallow furrows. Crown conical at first, broadening and becoming egg-shaped with age, rather sparse, with gently rising branches bearing long, hanging twigs. New branchlets quite variable in coloration, from yellowish brown to purplish brown, sometimes waxy, variably hairy, especially in the obvious grooves between the raised leaf bases. Young shoots (densely) orange brown pubescent, but sometimes nearly glabrous. Buds small, about 2-3 mm long, reddish brown to purplish brown, smooth or hairy, somewhat resinous. Needles of spur shoots straight or slightly curved, (10-)25-40(-50) on each spur, soft, (1-)2-3.5(-5.5) cm long and (0.6-)1-2 mm wide, bright green, turning bright golden brown in autumn before falling. Midrib prominently raised beneath and slightly so near the base above, with none to two incomplete and inconspicuous lines of stomates on each side above and 3-5 in a narrow white stomatal band on each side beneath. Pollen cones oblong (6-)10-20 mm long, yellowish brown. Seed cones larger (Larix gmelinii), (1.8)-3.5-4.5 × 1.5-3 cm, purplish green with bright reddish purple bracts before maturity, ripening dark to light brown with purplish brown bracts, on a short, curved stalk to 5(-7) mm long. Seed scales more numerous (16-30), dark red brown, convex, opening at 45º from the cone rachis. Bracts 15-20 mm long, much longer than the seed scales and curling down conspicuously to cover them, more or less spearhead-shaped, the long bristle tip to 5 mm long and either continuing down with the bract or curled back up. Seed body 4-5 mm long, spotted, the firmly clasping wing another 6-12 mm longer.

Recorded from NE China: Jilin, E Liaoning; North Korea; and the Russian Far East: Sikhote Alin Range; 400-1,800 m.

Conservation Status

Red List Category & Criteria: Near Threatened

The China Plant Specialist Group (CPSG) assessed this taxon (for its occurrence in China only, which is less than half of the global distribution) as Vulnerable under criterion A1c. This implies a population size reduction in excess of 50% over the last century. Although exploitation in North Korea and Russia (where the majority of trees occur) are unlikely to have been as severe, an overall decline is nevertheless likely. The extent of the decline is estimated to be less than 30% so that an assessment of Near Threatened (almost qualifies for listing as threatened under criterion A2d) is appropriate until more information is available.

This taxon is generally more montane in its occurrence than the other varieties, due in part to its distribution in regions with a less severely cold, semi-oceanic climate. It is, like the others, also found in the margins of swamps and lakes. It is found from 400 m to 1,800 m a.s.l.

Direct over-exploitation, surpassing rates of regeneration and re-growth, or preventing its return by forest management favouring other conifer species, are potential threats.

This taxon occurs in a few protected areas.

References

• Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
• Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
• IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland

Copyright © Aljos Farjon, James E. Eckenwalder, IUCN, Conifers Garden. All rights reserved.