Annual or perennial herbs. Leaves decussate or rosulate, sessile or subsessile, 1- or 3–5-nerved from base. Inflorescence terminal and/or axillary, cymose, appearing umbellate, or often reduced to 1 flower; flowers bisexual. Calyx, corolla and androecium 4-merous; calyx-tube c. as long as lobes; corolla urceolate, campanulate or c. trumpet-shaped, often bearded in mouth, lobes valvate in bud; stamens inserted in lower half of corolla-tube; ovary superior, styles 2, usually free at base, connate distally, stigma 2-lobed. Fruits a loculicidal capsule, apically 2-horned by the persistent style-bases; seeds many, minute.
About 54 species, in Asia, Malesia, New Caledonia, New Zealand and Australia; 48 species in Australia (43 endemic).