It contains highly poisonous alkaloids toxic to all classes of livestock and humans. Poison hemlock is often found on poorly drained soils, particularly near streams, ditches, and other water surfaces.
Stems are stout, hollow, ridged, and mottled with purple spots.
Crushed foliage has a disagreeable, mousy odor. Flowers are small, white, and borne in umbrella-shaped clusters about 3 inches across in early summer. Seeds are ridged and flattened, with 2 seeds borne together. The plant has a thick, white taproot, which, when cut longitudinally near the top, reveals thin, horizontal walls through a hollow chamber. No endorsement is intended or made of any hypertext link, product, service, or information either by its inclusion or exclusion from this page or site.