caulophyllum

from The Century Dictionary.

• noun A genus of plants, natural order Berberidaceæ, including one North American and two Asiatic species, perennial tuberousrooted herbs, bearing usually a single leaf and a raceme of flowers, succeeded by blue berries. The American species, C. thalictroides, known as blue cohosh, is reputed to have medicinal properties.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun blue cohosh