Cicuta maculata

spotted water hemlock, water hemlock, common waterhemlock, poison parsnip, spotted cowbane, spotted parsley, spotted water-hemlock, spotted waterhemlock, beaver poison, beaver-poison


Leaf Arrangement


Leaf Attachment


Leaf Margin

incised, serrate

Leaf Type

bipinnate, compound, tripinnate

Growth Form

forb, emergent aquatic, aquatic

Flower Color


Flower Month

May - August

Height (meters)

0.6 - 2.0

Milky Sap







biennial, perennial

Growing Season

Warm season

Wetland Class


Wetland Coefficient of Conservatism


Prairie Coefficient of Conservatism


Field Characters

Hollow, red spotted stems, veins in leaflets terminate at the notch between teeth, prominent calyx teeth visible on the flower and fruit, roots are a bundle of yellowish finger sized tubers. Similar to Conium maculatum that has no calyx teeth on flowers, veins that end in the point of the teeth on the leaflets, and a white tap root. Stem branches mainly near the top, alternate leaves with narrow to broad leaflets, fruits round with 10 ribs. Sometimes confused with elderberry (Sambucus canadensis) which has opposite leaves, woody stems that contain a corky pith, and many leaflets in its compound leaves. It is also sometimes confused with wild carrot (Daucus carrota) which is smaller, and has narrow, fern-like leaflets.

Cultural Information

Germination tests of this species were conducted in darkness at 21 C. by Corns (1960). There was no germination of either fresh seed or seed stored for 6 months. Gibberellic acid treatments were also not effective. Steffen (1997) reports seed germination improved with cold/moist stratification.

Animal Use

Very poisonous to livestock.

Natural History

A warm-season forb with hollow stems that reproduces by seed and rootstocks. It generally grows along streams, in marshes, and in other wet places throughout Louisiana and east, central and north Texas. It ranges throughout the eastern United States and Canada, south to Georgia and Louisiana, and west to the Dakotas and Texas. There are five species in the United States, all occurring in wet, marshy environments and all very poisonous. These deadly plants affect all warm-blooded animals, including humans. The tuberous roots are the most poisonous parts. USDA records indicate that a pea sized portion of the root will kill a man. Dried leaves and fruit are not thought to be dangerous, but poisoning cases have resulted from eating young shoots. The poisonous element is "cicutoxin," a clear, brown, sticky substance. The symptoms of poisoning are frothing at the mouth, nervousness, body tremors, and convulsions that end in death. Treatment is to promote vomiting.


Swamps, stream banks, marshes, wet meadows, and low roadside ditches.