Large woody vines, climbing to canopy by means of twining petioles. Stems often hollow, minutely puberulent with tiny simple 1-2-celled trichomes to densely pubescent with dendritic trichomes to 1 mm long, the trichomes sometimes enlarged at the base; new growth minutely puberulent to densely pubescent with dendritic trichomes. Bark of older stems dark reddish brown, glabrescent.
Sympodial units plurifoliate, not geminate.
Leaves simple or occasionally pinnately 2-3-lobed, (2.5-)6-15(-20) x (1.5-)3-9(-11) cm, elliptic to narrowly ovate, widest near the middle or in the basal third, coriaceous to chartaceous, the upper surfaces glabrous and somewhat shiny to pubescent with simple uniseriate trichomes along the veins to evenly pubescent on the veins and lamina with dendritic trichomes to 1 mm long, the lower surfaces glabrous (W Ecuador) to minutely simple puberulent to densely dendritic pubescent, the pubescence denser than that of the upper surfaces; primary veins 6-8 pairs, arching conspicuously to the petiole; base acute to truncate or cordate; margins entire or pinnatifid, the lobes to within 0.5 cm of the midrib; apex acute; petiole 1-6 cm, very variable in length along the stem, minutely puberulent to densely pubescent with dendritic trichomes like those of the stems and leaves, especially in the adaxial groove, twining.
Inflorescence terminal or sometimes lateral, 4-20(-30+) cm, several times branched, the branches very variable in length, with up to 100 flowers, finely and densely puberulent with tiny simple trichomes to densely pubescent with dendritic trichomes; peduncle 1.5-6 cm, not particularly distinct; pedicels 0.5-1 cm, 0.5-1 mm in diameter at the base, 1.5-2 mm in diameter at the apex, stout, spreading at anthesis, minutely puberulent to densely pubescent like the rest of the inflorescence, the pubescence sparser distally, articulated at the base from a small sleeve leaving a tiny peg on the inflorescence axis; pedicel scars more or less evenly spaced 2-5 mm apart on the flowering parts of the inflorescence rhachis.
Flowers all perfect, 5-merous. Buds narrowly ellipsoid and tapering, with a terminal pointed nipple, the corolla very exerted from the calyx tube early in bud. Calyx tube 1-1.5 mm, conical or broadly conical, the lobes apparently absent or mere apiculae from the rim to broadly deltate, glabrous to very minutely puberulent, the tips with a few uniseriate simple trichomes. Corolla 2-3 m in diameter, purple, violet or white, often with a mixture of colours, fleshy, deeply stellate, lobed nearly to the base, the lobes 12-16 x 1.5-2.5 mm, planar at anthesis, densely papillate on both surfaces with simple trichomes (papillae) to 0.3 mm, or the adaxial surface glabrous with only a few trichomes along the keeled lobe midvein, these giving the flowers a white cast in dried material, the tips cucullate. Filament tube minute, the free portion of the filaments markedly unequal, one anther with a longer filament 2-5 mm, the other 4 anthers with filaments 1-2 mm, glabrous or occasionally minutely puberulent with simple papillae within; anthers 5-8 x 1.5-2 mm, tapering, the base markedly sagittate to hastate, the lobes 0.5-1 mm, tightly connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 10-13 mm, usually equal in length to the longest anther, densely pubescent in the basal 2/3 (within the anther tube) with tiny dendritic trichomes to 0.5 mm long or very occasionally (W Ecuador) glabrous or only minutely puberulent, held tightly against the anther with the long filament; stigma capitate, occasionally somewhat bilobed, the surface minutely papillate.
Fruit a globose berry, to 2 cm in diameter, red, violet or metallic blue when ripe, not shiny, glabrous, the pericarp thin and leathery; fruiting pedicels to 1.5 cm, ca. 2.5 mm in diameter, apparently erect, but probably hanging from the weight of the berry.
Seeds 20-30 per berry, 3-7 x 2-5 mm, flattened-reniform, the surfaces appearing hairy from the lateral testa cell walls, these to 1 mm long, the testal cells pentagonal.