Description of the genus
Annual, glabrous or pubescent, small herbs. Leaves usually 1-pinnate,
pinnae toothed or lobed. Inflorescence terminal or axillary leaf-opposed
umbels. Peduncles glabrous or pubescent. Rays 3-10, glabrous or
pubescent. Bracts 3-5, margins scarious, ciliate; bracteoles 5-6,
papery, margins ciliate. Flowers white or pale purple. Calyx-teeth
reduced, adnate to ovary wall. Corolla with 5 petals, obovate or
obcordate, emerginate with long pointed tip. Stamens 5, filaments long,
anthers bithecous, hairy at base. Fruits oblong, oblanceolate, pubescent
or glabrescent, ridges obscure, unwinged furrows, vittae usually one
carpophore, bifid, mericarps dorsally compressed, hairs simple
intermixed with a few T-shaped.