Description: Herbs or subshrubs with cystoliths, branches often ribbed, usually constricted just above each node.
Inflorescences axillary or terminal, of 2–4-flowered clusters surrounded by an involucre and arranged in panicles, spikes or clusters; involucres of 2 outer bracts fused into a cylinder around the 2 inner bracteoles and flowers in varying stages of development. Calyx shorter than bracteoles. Corolla tube twisted through 180deg; 2-lipped with 'lower lip' (true upper lip) reflexed and entire or slightly notched, 'upper lip' erect, 3-lobed, frequently barred. Stamens 2, exserted. Ovary with 2 ovules per loculus.
Capsule narrow-oblong; seeds usually 4, glabrous, smoothly tuberculate.
Distribution and occurrence: World: c. 70 species, Africa, India, China, Malesia & Australia. Australia: 2 species (1 species endemic), Qld, N.S.W., N.T., W.A.
Text by J. Everett