Annual, biennial, or sometimes perennial herbs, erect initially, later procumbent viny herbs with branches extending to 4 m from center. Stems 10-14 mm in diameter at base, green, pubescent and usually villous towards the apex, with a mixture of numerous simple unicellular trichomes to 0.5 mm long and sparse simple uniseriate multicellular trichomes to 3 mm long and composed of up to 10 cells, some gland-tipped, particularly the longer ones, giving the plant a strong scent.
Sympodial units 3-foliate, internodes 1-6(+) cm long.
Leaves interrupted imparipinnate, (10-) 20-35 (+) cm long, (3-) 7-10 (+) cm wide, sparsely pubescent with a mixture of simple unicellular and simple uniseriate multicellular trichomes like those of the stems on both surfaces; primary leaflets 3-4 (-5) pairs, 3-7 cm long, 1-4 cm wide, ovate or elliptic, the base oblique and basiscopically decurrent, truncate to cordate, the margins dentate or crenate mainly near the base, rarely entire or deeply dentate or lobulate, the apex acute to attenuate; terminal primary leaflet usually larger than the laterals, 3-5 cm long, 1.5-3 cm wide, the petiolule 0.5-1.5 cm long, the apex usually attenuate; lateral leaflets 2-4.5 cm long, 0.8-2.5 cm wide, the petiolule 0.3-2 cm long; secondary leaflets present mainly acroscopically on basal leaflets, 0.2-0.8 cm long, 0.1-0.5 cm wide, sessile or with a short petiolule to 0.4 cm long; tertiary leaflets absent; interjected leaflets usually present, 6-10, 0.1-0.8 cm long, 0.1-0.6 cm wide, the petiolule 0.1-0.3 cm long; petiole 1.2-6 (+) cm long; pseudostipules absent.
Inflorescences to 10 cm long, usually simple, rarely with 2 branches, with 5-15-flowers, peduncle less than 3 cm long, pubescent like the stems. Pedicels 1-1.2 cm long, articulated in the distal 1/3. Buds 0.5-0.8 cm long, 0.2-0.3 cm wide, conical, straight, with the corolla about halfway exserted from the calyx just before anthesis.
Flowers with the calyx tube minute, the lobes to 0.5 cm long, linear, pubescent with long and short simple uniseriate trichomes the apex acute; corolla 1-2 cm in diameter, pentagonal, bright yellow, often fasciated and with more than 5 lobes in some cultivars, the tube 0.2-0.4 cm long, the lobes 0.5-2 cm long, 0.3-0.5 cm wide, narrowly lanceolate, sparsely pubescent with tangled uniseriate trichomes ca. 0.5 mm long the tips and margins, the lobes spreading at anthesis; staminal column 0.6-0.8 cm long, 0.2-0.3 (-0.5) cm wide, narrowly cone shaped, straight, the filaments minute to 0.5 mm long, the anthers 0.4-0.5 cm long, the sterile apical appendage 0.2-0.3 mm long, always less than half the total anther length; ovary conical, minutely glandular villous; style 0.6-1 cm long, <0.5 mm in diameter, usually included in the staminal column, but exserted in facultatively allogamous populations; stigma capitate, green.
Fruits 1.5-2.5 (-10 in some cultivars) cm in diameter, usually globose, 2-locular, but often of varying shape and/or multilocular, glabrescent and becoming red, yellow or deep orange at maturity; fruiting pedicels 1-3 cm long, straight or angeld towards the inflorescence axis at the articulation, thickening in large fruited varieties; calyx lobes in fruit accrescent, ca. 0.8-1 cm long, 0.2-0.25 cm wide, somewhat to strongly reflexed.
Seeds 2.5-3.3 mm long, 1.5-2.3 mm wide, 0.5-0.8 mm thick, obovate, pale brown, pubescent with hair-like outgrowths of the lateral testa cell walls, these adpressed and giving a silky appearance to the surface or more often shaggy, narrowly winged (0.3-0.4 mm) at the apex and acute at the base.