Plants perennial, finely pubescent, from stout taproots. Stems prostrate to erect, often clambering through other vegetation, slender to ± stout, herbaceous or woody, unarmed, without glutinous bands on internodes. Leaves sessile to petiolate, subequal to greatly unequal in each pair, ± thick and succulent, base asymmetric or ± symmetric. Inflorescences terminal or axillary, solitary flowers or few-flowered cymes and nearly sessile, or short pedicellate in 3-25-flowered umbellate clusters in axils or forks of branches; bracts persistent, not accrescent, 1-3 beneath each flower, distinct, narrowly lanceolate, small or minute, herbaceous. Flowers bisexual, chasmogamous and/or cleistogamous; cleistogamous perianth narrow domelike tube atop basal portion; chasmogamous perianth radially symmetric, short to elongate funnelform, constricted beyond ovary, abruptly expanded to 5-lobed limb; stamens 2(-3) or 5-6 (2-5 in cleistogamous flowers), exserted; styles exserted beyond anthers; stigmas peltate. Fruits oblong or narrowly ellipsoid, coriaceous, smooth, glabrous or minutely puberulent; ribs 5, rounded, often with large, dark, sticky gland near apex, or wings 3-5, coriaceous, hyaline, often between ribs or wings a rib or low sharp ridge. R. A. Levin (2000) showed that Selinocarpus is paraphyletic and embedded within Acleisanthes. All species are pubescent on young stems and leaves. Older leaves may be glabrate or glabrous.