Small shrubs with erect branched stems. Leaves paired or in whorls of 3, petiolate. Stipules with (1)3–5 linear or filiform colleter-tipped setae from a short base adnate to petioles. Flowers medium-sized, hermaphrodite, dimorphic, some flowers with anthers included and style exserted and others completely vice versa, in rather dense few-many-flowered terminal corymbose inflorescences. Calyx tube narrowly obconic or turbinate, ribbed; limb variously deeply 4–5-lobed or, in sect. Dirichletia, nearly always eccentrically elliptic, the tube ± placed at one of the foci, sometimes shallowly 3-lobed. Corolla tube very narrowly cylindrical; lobes 4–5, oblong or ovate; throat densely hairy. Ovary 2–3-locular, each locule with a slender basal placenta bearing c. (3)4–6 ovules; style filiform, the stigma divided into 2(4) filiform lobes. Fruit obconic, sometimes curved, of bony texture, strongly ribbed, the ribs running out into the strongly nervose accrescent calyx limb or lobes, apparently always indehiscent, 1–2-seeded. Seeds narrowly oblong-obconic.