Erect annual or perennial herbs, saprophytic or not, usually unbranched, green or not, 3-40 cm. high. Stems with small alternate colourless scale-like leaves. Basal leaves usually minute, lanceolate, scale-like, up to 2 mm. long, or a basal rosette of larger, linear, imbricate green leaves, sometimes very few in number. Inflorescence terminal, sometimes a single flower, or a dense cyme of 2-30 flowers. Perianth regular, blue, white, or rarely yellow; tube cylindric or trigonous, prominently 3-angled, winged, ridged or not; tepals 3 or 6, persistent; inner tepals smaller than triangular outer tepals, or lacking. Stamens 3, in the perianth-tube below the inner tepals, sessile or subsessile, basifixed; thecae globose or clavate, dehiscing transversely; connective with entire or forked to bilobed crest above and sometimes with basal spur. Ovary 3-locular, with axil placentas, often 3-winged with the perianth; style entire or shortly 3-lobed, equal to the perianth-tube; stigma terminal on style or style-branches. Capsule 3-angled or 3-winged, crowned by persistent perianth, dehiscing irregularly by slits between the wings. Seeds ellipsoid, oblong or subglobose; testa thin, reticulate or striate, usually adpressed.
Sp. Pl.: 287 (1753) & Gen. Pl., ed. 5: 139 (1754); G.P. 3(2): 457 (1883); C.H. Wright in F.T.A. 7: 11 (1897) & in Fl. Cap. 5(3): 2 (1913); Jonker in Med. Bot. Mus. Rijksuniv. Utrecht 51: 57 (1938); H. Perrier in Fl. Madag. 48: 2 (1946); Hepper in F.W.T.A., ed. 2, 3: 179 (1968); Geerinck in F.C.B., Burmanniaceae: 3 (1970)