The blue cohosh is also called papoose-root, squaw-root, blue ginseng, yellow ginseng, blueberry-root.
The blue cohosh is a perennial from one to three feet high, with an erect stem bearing a large nearly sessile leaf near the summit and a loose cluster of greenish-purple flowers, which are in full bloom before the leaf has unfolded. The whole plant has a peculiar dark greenish purple bloom when young, which gradually disappears with age. The leaf is twice or thrice compound, the first divisions being long-stalked and the leaflets shorter stalked, oval or oblong, with three to five lobes near the apex. The flowers are about one-half inch wide, surrounded by three to four small bracts. The sepals are six, much longer than the six small and rounded petals. The seeds are globular, resembling dark-blue berries, borne on short, stout stalks. The rootstock is horizontal, thick and knotted, with round pits or leaf scars at intervals, each scar representing a year's growth. It is one of the early spring flowers, blooming from April to May.
This native Canadian plant is found in the woods from New Brunswick to Manitoba.
Blue cohosh contains the poisonous glu-cosidal saponine, a peculiar substance which, when stirred in water, creates a froth like soap suds. The plant is extremely bitter to the taste and is hardly likely to be eaten except by children tempted by the attractive appearance of the berry-like seeds. Lloyd records blue cohosh, in White's book on dermatitis, as being "very irritant to mucous surfaces, so much so that the dust is very disagreeable." The rootstock is said to contain saponin and the alkaloid caulophylline.