Any of 10 species of coniferous evergreen trees that make up the genus Tsuga , in the pine family, native to North America and central and eastern Asia.
Some are important timber trees, and many are popular ornamentals. Other plants commonly called hemlock include ground hemlock (see yew ) and poison hemlock and water hemlock ( parsley family). A true hemlock is a tall, pyramidal tree with purplish or reddish-brown bark, slender horizontal or drooping branches, and short, blunt leaves that grow from woody cushionlike structures on the twigs.