Hemlock trees are not the source of the poison hemlock that killed Socrates. They are not poisonous and not even related to poison hemlock, but the foliage looks similar, and crushed needles have a similar smell. This, no doubt, led European settlers of North America to call these trees hemlocks. The scientific name of the hemlock genus is Tsuga, which also has a curious origin. Rather than the usual Latin name, Tsuga is the Japanese name for Japanese hemlock. In the nineteenth century, hemlocks were first classified as a pine, then as a fir, and later as a spruce. After the discovery of Japanese hemlock, hemlocks were assigned to the genus Tsuga.
Hemlocks are in the pine family (scientific name: Pinaceae) and are unique in the family. They have a distinctive drooping leader at the top of the tree. Hemlocks also have the smallest cones in the pine family. They can tolerate growing in the shade of other large trees for years. However, hemlocks can grow to enormous size and eventually dominate other trees in the forest. Although they can grow in the shade of Douglas fir for hundreds of years, in the normal succession of a Douglas fir forest, the hemlocks will eventually prevail, forming the canopy of the mature forest.
|Western hemlock at Elk Mountain|
Tsuga at conifers.org
Tsuga in Wikipedia