2. Croomia Torrey in Torrey & A. Gray, Fl. N. Amer. 1: 663. 1840.
黄精叶钩吻属 huang jing ye gou wen shu
Herbs perennial. Rhizomes creeping, rooting from nodes. Roots slightly fleshy. Stems usually erect, simple. Proximal leaves scalelike, distal ones few to several, alternate, membranous. Racemes spreading, 1--4-flowered; peduncle axillary, slender; bracteoles small, scalelike. Flowers small. Stamens inserted at base of perianth segments; filaments thick; anthers dorsifixed, arched; connective not appendaged. Ovary superior, ovoid, compressed; ovules few, apically attached to placenta, pendent. Stigma capitate. Capsule ovoid, valvate. Seeds subglobose, longitudinally ribbed; funicle bearded.
Three species: China, Japan; E North America; one species in China.
Wu Zhengyi (editor’s note) believes that Croomia, together with Stichoneuron J. D. Hooker (from SE Asia), are more primitive and should be treated in the segregate family Croomiaceae, as was done by Takhtajan (Diversity Classific. Fl. Pl. 519. 1997).