For such a common foundation and landscape plant, yews have a rich and lengthy history. They belong to the genus, Taxus, and while there are a dozen or so species, only a handful are commonly grown in the United States although they may include hundreds of cultivars. Often yews are appreciated for their ability to accept a remarkable amount of pruning.
First signs of a recognizable yew species, Paleotaxus rediviva, were found in 200 million year old strata of the Triassic period. Taxus jurassica remains, that more closely resembled our current Taxus species including English (T. baccata) and Japanese (T.cuspidata) yews, dated back 140 million years.
English yews are hardy to zone 6 so while they had a significant historical impact in Europe, they would be most successfully grown here as ornamentals in the warmer parts of Connecticut or more sheltered areas. They are very long-lived trees; some estimated to be more than 2000 years old. The species can reach 35 to 60 feet high with about a 20-foot spread but larger specimens have been recorded. In Great Britain and other parts of Europe, they are commonly planted near churches. There has been much speculation as to why. Were they the symbol of death or rebirth, did they imbue a feeling of immortality with their evergreen branches, offer protection to buildings or being poisonous, keep grazing animals away from cemeteries? Whatever the reason, there are many old yews in British churchyards.
Not only did they have a religious significance, but their wood was highly sought after for longbows with the oldest surviving one dated to between 4040 BC to 3640 BC and now on display at the National Museum of Scotland. Apparently, yew wood was in such demand for long bows that much of the yew stock throughout Europe was depleted by the 17th century.
Two species of yews are native to North America. The Canadian yew (T. canadensis) would naturally be found in rock ravine communities from southern Canada to Virginia. It has a low scraggly growth habit and prefers the cool, shady conditions of coniferous forests. One cultivar, ‘Stricta’, serves as a very hardy, shade loving groundcover.
On the west coast, Pacific yews (T. brevifolia) reach up to 15 feet high and are typically found as understory trees or large shrubs in coniferous ecosystems of the Pacific northwest. They serve as a valuable food source to birds as well as ungulates such as deer, moose and elk. Native Americans used the wood for many purposes including bows.
In the 1960s, the National Cancer Institute discovered the Pacific yew bark contained a compound, taxol (later renamed paclitaxel), that could more effectively treat certain types of cancer including breast, prostrate and ovarian. Large numbers of Pacific yews were being harvested as it was estimated that 3 mature trees were needed to treat one patient. This led to unsustainable harvesting and concerns from environmentalists as well as the general public. New techniques led by Bristol-Myer Squibb resulted in a synthesized version so Pacific yew populations are no longer at risk. A European firm was able to produce another anti-cancer drug, docetaxel, from the needles of the European yew so plants can be left intact.
While I have a whole hedge of yews bordering part of our property, I have no idea what species they are. It seems that in the local nursery trade, English and Japanese yews are fairly common and perhaps even more so, the hybrid between the two, Anglojap yew (Taxus x media). This hybrid was developed in the early 1900s by T.D. Hatfield of the Hunnewell Pinetum in Wellesley, MA. A dozen or more named cultivars exist and vary by size, form, growth rate, winter hardiness and even sex. Yews are dioecious, meaning male and female sex parts occur on separate plants.
For anyone not familiar with yews, these evergreen shrubs and trees have needle-like, mostly dark green, ½ to ¾ inch leaves that are somewhat spirally arranged on the stem but a twist at the leaf base aligns them in two rows.
Male yews have 1/8 to ¼ inch globose (rounded) cones that shed pollen in the spring. The cones of female yews contain a single seed surrounded by a red, fleshy, berry-like structure called an aril. Every part of a yew plant, except the fleshy fruit is poisonous – at least to humans, pets and livestock. Males clones might be chosen as landscape plants if the red fruit will attract curious children.
As mentioned earlier, birds can feed on the fleshy fruit and the poisonous seed will pass through their system and be expelled in their droppings. How deer manage to eat our yews and not die, remains a mystery but obviously their systems are able to break down any toxins or so much grazing damage would not occur.
In most instances, yews are kept fairly tightly trimmed so the main stems really aren’t visible but occasionally more mature specimens are encountered. On older tree forms, the bark is a flakey, furrowed, reddish brown – quite compelling whether looking at the yew as a landscape specimen or considering its historic role in Europe’s ecclesiastical landscape.
Here’s to yew!
Dawn P.
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