lection

yew

23 march 2020

There are no yew trees in our garden. This is Texas, and I associate yew trees with northern climes, cemeteries, and English longbowmen.

Though Fred Hageneder sets me straight in Yew, his global history for the Reaktion Botanical series. "Taxus baccata," says Hageneder, "is not just a resident of cool and wet northern countries but can adapt to a whole spectrum of local climates" (21). Adaptable within limits, of course. Yews can't take high heat, drought, or prolonged deep frost; they are certainly temperate-zone plants. But they grow in some surprising venues – southern China, Indonesia, the Mediterranean including Morocco – often seeking out higher altitudes in lower latitudes.

Not that trees really seek climates out. Or do they? Hageneder ascribes more agency to plants than many a botanical writer would. Yews seem to employ what humans can only call strategies. They change sex. They cope with damage and age by finding new ways to grow. They shift between welcoming sunlight and existing in deeper shade than almost any other kind of tree.

Yews deploy a curious balancing act between poison and palatability. Every part of a yew tree is poisonous, says Hageneder, except the bright red aril that surrounds its seed. The latter feature is a crafty strategy ensuring that birds distribute seed widely, and not unique to yews. Nor is poison. But the yew's poison is oddly and selectively deadly, in ways that don't seem strategic. Yew poison deters some fungi, but other fungi are vital to the yew's life cycle, and thus unharmed. Eating yew kills insects, and also kills horses. It kills people too, but spares deer and rabbits – in fact, predation is a big part of yew ecology, despite the extreme measures the plant takes to protect itself.

The toxic qualities of the yew have brought great relief to cancer patients. Taxanes, one of a suite of poisonous chemicals produced by yews, have been mobilized, in the past 30 years, as a major component of chemotherapy drugs. At last, a poison for something that needs poisoning: malignant tumors.

Hageneder speculates that, etymologically, toxin may be related to taxus, the Latin and scientific name for the yew. Certainly the word toxon, Greek for "longbow," is in the same word family. Perhaps arrows, poisons, even poison arrows are all connected conceptually and linguistically with yews. Longbows, in any event, were made, historically, from yew wood. Hageneder charts a remarkable history of European trade in the early-modern period, in which English demand for weapons-grade wood deforested great swaths of the Continent.

In Hageneder's view, both the longbow craze and the taxane boom were disasters for the yew as a species. Local populations were wiped out in both cases, and so were their oldest members, the gnarled, complicated, and ever-strategic "ancient yews" that still exist here and there, centuries old and for practical purposes immortal, because of their regenerative powers. Though it should be noted that there was no upside to longbows; they existed to kill people. Decimating a species to cure breast cancer may not be any more commendable, from a posthuman standpoint, but it's got to be better in some sense than peppering the French chivalry with arrows.

Hageneder is strong on yews in myth and poetry. The Romantics established the yew as a poetic plant, but Hageneder points to T.S. Eliot as the major yew poet in English. He invokes "Ash Wednesday" as the center of Eliot's uses of the yew, where a "veiled sister" is mysteriously connected to the tree. But the yew persists into the later Four Quartets, where in "Little Gidding" "The moment of the rose and the moment of the yew-tree / Are of equal duration." I'm not sure what that means. (It means what it says, Eliot would say.) Love and death? Sounds Romantic enough to me.

Hageneder illustrates much of his text with his own photographs of improbably elderly yew trees. He seems to have made many pilgrimages to visit these "veterans," in England especially. He laments the lack of legal protections for these trees in England, where churches shelter some of the most remarkable specimens but seem to have little veneration for their botanic uniqueness. It would seem fitting if the nation that extirpated so many yews elsewhere would devote itself as a sanctuary to its own.

Hageneder, Fred. Yew. London: Reaktion, 2013.

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