Climbing, woody shrub; leaves in whorls of 3-4, sometimes opposite, up to 15 cm long, obovate or oblanceolate, acuminate at apex, cuneate at base; petioles very short with interpetiolar glands; flowers large, showy, yellow in terminal or axillary peniculate or umbellate cymes; calyx 5-lobed, lobes free, ovate-oblong; corolla yellow, 5-9 cm across, cylindric in the lower half, spreading in the middle, densely villous with a ring of white scales at the throat, lobes shorter than tube, overlapping to the left; stamens-5, epipetalous, included, anthers sagitate, mucronate, bent at the tip of stigma, filaments slender; ovary 1-celled, ovules many on parietal placenta, style short, stigma depressed; capsule globose or subglobose; seeds numerous, minutely winged.