Description: Herbs, with procumbent to erect, usually much-branched stems.
Leaves opposite or apparently in whorls of 4; stipules scarious, conspicuous.
Flowers small in branched leafless cymes, bracts scarious, often concealing flowers. Sepals 5, hooded, strongly keeled, often awned and with membranous margins. Petals 5, minute or 0. Stamens 3–5. Styles 3, united towards base.
Capsule shorter than calyx, opening in 3 valves.
Distribution and occurrence: World: 16 species, warm regions of world. Australia: 1 species (naturalized).
Text by A. Doust