Plants 1-3 m tall, glabrous. Leaves petiolate, bipinnate; segments oval, deeply serrate. Involucre of 5-8 minute, linear to oval bracts. Rays 8-20, unequal, glabrous. Involucel of 3-5, 1-2 mm long, linear to ovate bractlets. Pedicels 2-3 times longer than the flowers. Fruit broadly ovoid, 2-3 mm long, 2-2.5 mm broad; ridges prominent, obtuse, undulate; styles reflexed; vittae numerous, minute.

Fl. Per. June to August.

Type: Described from Europe.

Distribution: North and South America, Europe, Middle East, Central Asia, Afghanistan, India, W. Pakistan, China.

Hemlock is a large poisonous plant growing near cultivation and moist waste places in the hills and is used in spasmodic and convulsive diseases. An alkaloid, conine, is found in the fruit.