Alternate name: Spotted Water Hemlock

Family: Apiaceae, Carrot view all from this family

Description Smooth, erect, highly branched plant bearing dome- shaped, loose clusters of small white flowers. The sturdy stem is magenta-streaked.
Flowers: florets about 1/6" (4 mm) long; no bracts beneath flattened umbels, 3" (7.5 cm) wide.
Leaves: lower ones to 1' (30 cm) long, doubly divided, sharp-pointed, toothed, veins ending at notches between the teeth.
Fruit: round, flat, with thick ridges.
Height: 3-6' (90-180 cm).

Warning All parts of this plant are deadly poisonous if eaten. Only a very small quantity can cause death. The roots have been mistaken for parsnips and other common root crops, with fatal results; cattle, horses, and sheep have died from grazing on it. Children can be poisoned by blowing through whistles made from the stalks. Sensitivity to a toxin varies with a person’s age, weight, physical condition, and individual susceptibility. Children are most vulnerable because of their curiosity and small size. Toxicity can vary in a plant according to season, the plant’s different parts, and its stage of growth; and plants can absorb toxic substances, such as herbicides, pesticides, and pollutants from the water, air, and soil.

Flower June-September.

Habitat Wet meadows, thickets, freshwater swamps.

Range Southern Ontario to Nova Scotia; south through New England to Florida; west to Texas; north through Missouri to Canada.

Discussion The plant is not related to true Hemlock (Tsuga spp.), but to Poison Hemlock (Conium maculatum), the plant used to poison Socrates.