Bot. Reg. 5: 742, t. 435 (1819). — Type:

Cryptostegia grandiflora R. Br.

Woody liana to shrub with scrambling branches, usually 2-3 m high and self-supporting but sometimes climbing up to 10 m high; branches glabrous to hairy, with lenticels. Leaves decussate, somewhat coriaceous; blade usually oblong or elliptic to ovate, almost truncate to usually tapering at base into a distinct glabrous to hairy petiole, usually acuminate at apex, glabrous to hairy; venation looped, with finely reticulate and distinctly visible veinlets below when dry; mid-rib when dry ± even with leaf surface above to slightly impressed, raised below.

Inflorescences in terminal, mono- to dichasially branched, usually hairy cymes. Flowers 1-5 but sometimes up to 9, c. 3 cm long or more; bracts narrowly triangular, caducous, usually hairy. Calyx lobes narrowly ovate to elliptic, acute to usually acuminate, shorter than the corolla tube, hairy; margins sometimes reflexed. Corolla slightly twisted in bud, with the lobes fused for (1/4-)1/3-2/5(-1/2) of their length into a tube, campanulate to salverform, glabrous to hairy outside, glabrous inside, white to pink; tube ± cylindric, slightly widening towards the mouth, glabrous inside; lobes narrowly ovate to elliptic, acute to rounded at apex, erecto-patent or bent outwards. Corona lobes inserted in the tube below the sinuses of the corolla lobes, free, entire to bifid, filiform, ± straight, covering the staminal cone, glabrous. Stamens inserted at the base of the corolla tube, included, glabrous; filaments short, inserted at a distance below the corona lobes; anthers with distinct and narrow protruding connective up to 1.5 mm long. Translators placed in 5 cavities at the style head; spathe rounded to ovate, obtuse to acute at the apex; stipe present; viscidium flat. Style disinct, glabrous.

Follicles narrowly ovoid to fusiform, straight to boat-shaped, ± triangular with 3 longitudinal wings, acute at apex and often with a small hook, thick-walled, recurved 90° at base, glabrous to finely pubescent. Seed surface tuberculate or with shorter ridges.