乌头属 wu tou shu

Li Liangqian; Yuichi Kadota

Herbs perennial or pseudoannual, rarely annual, with taproots or 2 to several caudices. Stem erect or twining. Leaves simple or compound, cauline ones alternate, sometimes all basal, palmately divided, rarely undivided. Inflorescence usually racemose. Pedicel with 2 bracteoles. Flowers bisexual, zygomorphic. Sepals 5, petaloid, purple, blue, or yellow; lower sepals 2, narrowly lanceolate or oblong, small; lateral sepals 2, suborbicular; upper sepal falcate, navicular, galeate to cylindric. Petals 2, clawed; limb usually with lip and spur, secretory tissue usually at limb apex, rarely abaxial. Staminodes usually absent. Stamens numerous; anthers ellipsoid-globose. Carpels 3--5(--13); style short, persistent.

About 400 species: temperate regions of the N hemisphere; 211 species (166 endemic) in China.