Description from Flora of China
Herbs biennial or perennial, caulescent or acaulescent, usually glabrous. Taproot fusiform or stout. Stem solitary, creeping to erect, branched above. Leaves simple; petioles sheathing; blade entire, pinnately or palmately parted or divided, leathery or membranous, venation parallel or reticulate, margin often ciliate to spinose. Umbels simple, capitate forming globose to cylindrical heads; heads solitary or in cymes, sometimes racemes; bracts 1 to several, entire or divided, subtending the head; bracteoles 1 to many, subtending the individual flowers. Flowers small, bisexual, sessile. Calyx teeth prominent, persistent, ovate to lanceolate, acute to obtuse. Petals white or purple, ovate to oblong, with incurved apex. Stylopodium absent; styles shorter than or exceeding the calyx teeth. Fruit globose to obovoid, scarcely flattened laterally, variously covered with scales or tubercles; ribs obsolete; vittae mostly 5, inconspicuous; commissure broad. Seed subterete in cross section, face plane or slightly concave. Carpophore absent.
Between 220 and 250 species: tropics and temperate regions worldwide, especially South America; two species in China.
(Authors: She Menglan (佘孟兰 Sheh Meng-lan); Mark F. Watson)