All species of yew contain highly [[poison]]ous [[alkaloid]]s known as [[taxane]]s, with some variation in the exact formula of the alkaloid between the species. All parts of the tree except the [[aril]]s contain the alkaloid. The arils are edible and sweet, but the seed is dangerously [[poison]]ous; unlike birds, the [[human]] stomach can break down the seed coat and release the taxanes into the body. This can have fatal results if yew 'berries' are eaten without removing the seeds first. Grazing animals, particularly [[cattle]] and [[horse]]s, are also sometimes found dead near yew trees after eating the leaves, though [[deer]] are able to break down the poisons and will eat yew foliage freely. In the wild, deer browsing of yews is often so extensive that wild yew trees are commonly restricted to cliffs and other steep slopes inaccessible to deer. The foliage is also eaten by the [[larva]]e of some [[Lepidoptera]]n [[insect]]s including [[Willow Beauty]]. | All species of yew contain highly [[poison]]ous [[alkaloid]]s known as [[taxane]]s, with some variation in the exact formula of the alkaloid between the species. All parts of the tree except the [[aril]]s contain the alkaloid. The arils are edible and sweet, but the seed is dangerously [[poison]]ous; unlike birds, the [[human]] stomach can break down the seed coat and release the taxanes into the body. This can have fatal results if yew 'berries' are eaten without removing the seeds first. Grazing animals, particularly [[cattle]] and [[horse]]s, are also sometimes found dead near yew trees after eating the leaves, though [[deer]] are able to break down the poisons and will eat yew foliage freely. In the wild, deer browsing of yews is often so extensive that wild yew trees are commonly restricted to cliffs and other steep slopes inaccessible to deer. The foliage is also eaten by the [[larva]]e of some [[Lepidoptera]]n [[insect]]s including [[Willow Beauty]]. |