Tsuga is a genus of conifers in the family Pinaceae. The common name hemlock is derived from a perceived similarity in the smell of the crushed foliage to that of the unrelated herb poison hemlock. Tsuga species are not poisonous.
There are four North American species. The two eastern North American species, T. canadensis and T. caroliniana are under serious threat by the sap-sucking insect Adelges tsugae (Hemlock Woolly Adelgid). This adelgid, related to aphids, was introduced accidentally from eastern Asia, where it is only a minor pest.
The Common North American Hemlocks
Leaves: persistent or deciduous, linear or needle-like.
Fruit: Woody cones.