Shrubs or small trees, pubescent, villous or glabrescent. Bark smooth, rarely fibrous, with lenticels. Leaves in whorls of 3, rarely paired or 4 or 8; petiole short or absent. Conflorescence terminal or on short, lateral shoots and appearing axillary, sessile or subsessile, 1-7 (-19)-flowered. Bracts numerous; outer very short; inner long and reaching half-way up perianth or exceeding it, red, yellow or green. Flowers actinomorphic or zygomorphic, bisexual. Perianth tubular, but often with 4 free segments from base to 3 mm up tube, pilose, hirsute or glabrous; limb 4-lobed, with 1 stamen in each lobe, becoming tightly revolute. Stamens sessile or very shortly pedicellate, with or without an apical gland. Hypogynous glands (2-) 4, free or fused or absent, glabrous or occasionally with indumentum. Ovary densely strigose or hirsute; style exceeding open perianth, narrow, glabrous or sparsely hirsute or pilose; stigma less than 1 mm long, with apical groove or pit, or 2-lobed, distal to slightly swollen pollen presenter. Fruit a follicle, sessile or subsessile, splitting when seeds ripe, smooth or spiny especially along suture, with stylar beak and a pair of prominent horns at distal end of suture. Seeds (1) or 2, narrowly winged, flat or slightly domed on 1 side, finely papillate, mottled black and brown.
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