I. Subfam. Weddellinoideae (Warming) Engler (1928).

Young flowers not enclosed in spathella or cupule; tepals (4)5(6), imbricate; stamens 5--25, free; pollen tricolporate, shed in monads; ovary 2-locular; capsule opening by 2 equal valves; valves with 1 rib-like midrib and 2 lateral ribs. Only one genus Weddellina Tulasne, northern to central South America.