Description: Annual or perennial herbs; stems prostrate to erect.
Leaves spirally arranged or distichous; lamina glabrous, sessile.
Inflorescence terminal or terminal and axillary; bracteoles persistent, cup-shaped. Flowers actinomorphic or slightly zygomorphic. Outer tepals free, mostly green; inner tepals free, petaloid, blue, purple or white (rarely yellow). Fertile stamens 3 (sometimes 2), opposite the outer tepals, filaments bearded, anthers dehiscing by slits; staminodes 3 or absent, opposite the inner tepals, filaments bearded or glabrous. Ovary 3-locular; ovules 1–8 per loculus.
Fruit a 3-valved capsule; seeds greyish to dark brown, smooth or ornamented.
Distribution and occurrence: World: c. 50 species, tropical regions. Australia: 5 species (1 species endemic), Qld, N.S.W., N.T., W.A.
Text by Peter G. Wilson
Taxa not yet included in identification key