Description from Flora of China
Dipetalia Rafinesque, nom. rej.; Ellimia Nuttall, nom. rej.
Herbs annual, biennial, or perennial. Leaves alternate or fasciculate, linear, entire. Flowers borne in terminal spikes, whitish. Sepals 4-parted. Petals 2, free or connate at base. Stamens 3-8, free or connate at base; disc absent. Ovary 4-angled; placentas 4, parietal; ovules numerous. Capsule angled. Seeds numerous.
Three species: two in S Africa, the other in N Africa, S Asia, N Atlantic Islands, and SW North America; one species in China.