Annual or sometimes perennating, glabrous herb, 15-30 cm tall. Leaves exstipulate, sessile or subsessile, alternate to opposite, almost entire, acute, 1-2 x 0.1-0.3 cm, all leaves (floral, umbel and cauline) similar in shape but floral smaller in size. Cymes usually terminal, 3-rayed pseudoumbels, each ray 1 to several times divided. Cyathia about 1 mm across, short-pedunculate; glands greenish, 2-horned. Capsule 3-lobed, 3-3.5 mm across, exserted on a recurved small pedicel, smooth, glabrous, lobes rounded. Seeds ovoid-cylindric, usually tuberculate-rugose, greyish with dark purple patches, 2-2.5 mm long, carunculate.