Glabrous or hairy, erect annual. Stems up to c. 1 m high, branched or not at base. Lvs alternate, exstipulate, sessile, finely serrate, obovate to oblong-lanceolate, acute, cordate at base, 10-40-(60) mm long. Terminal umbel usually 5-rayed, with usually few to several axillary rays arising below; lvs subtending rays similar to stem lvs; rays secondarily branched and then forming compound dichasia; lvs subtending ray-branches and cyathia all deltate. Glands suborbicular, entire. Capsule shallowly grooved, with conspicuous tubercules. Seeds smooth, rounded, slightly flattened, usually olive-brown, 1.8-2.2 mm long.