(This article is about plants named "hemlock." There is also a place in Michigan by that name: see Hemlock, Michigan.)
Several plants are called hemlock.
- Poison hemlock is a common European plant, Conium maculatum, family Apiaceae (formerly Umbelliferae); it is toxic, containing the alkaloid Coniine.
- Water hemlock is Cicuta virosa, another deadly plant in the Parsley family.
Quite different from these are the conifers
- Western hemlock, Tsuga heterophylla. This is particularly common in the Pacific Northwest of North America.
- Eastern hemlock Tsuga canadensis.
- Mountain hemlock Tsuga martensiana.
Hemlock, Queen Anne's Lace, and Parsnip commonly grow in ditches in most temperate regions of the globe.