High climbing woody vine, stems glabrate. Leaves trifoliolate, the leaflets mostly 9-12 cm long, ovate, apically acuminate, basally obtuse or truncate, 3-4 veined from the base, above glabrous except for appressed ascending hairs on the principal veins, beneath sparingly short pilose to glabrous, the principal veins with stout, mostly appressed and ascending yellowish or brownish hairs, often tufted at the very leaf base; petiolules 7-9 mm long, pubescent, drying dark; petioles mostly about as long as the terminal leaflet, glabrate; stipels linear, ca. 3 mm long; stipules 3-4 mm long, ascending pubescent. Inflorescences short racemes, the peduncle 4-13 cm long, the pedicels subumbellate in bud, often becoming well spaced in flower, ca. 10 mm long, appressed pubescent, becoming 10-20 mm long and stout in fruit; bracts subfoliaceous, velutinous on both sides, early caducous, perhaps confined to the lower portion of the inflorescence. Flow-ers showy, yellow or orange, calyx oblique cupular, softly velutinous with minute hairs inside and out, and with scattered stout hairs on the cup outside, 2-3 cm long, the upper 2 teeth united into a broadly obtuse hood or into a deltoid lobe 5-8 mm long, the lower 3 teeth narrowly deltoid to linear, ca. 10 mm long; corolla mostly drying black, 6-9 cm long, the standard 1/2-2/3 as long as the wings, to 5 cm long, the wings mostly rhomboidal, to 1.8 cm wide, sometimes slightly acu-minate; keel narrowly falcate, the apex indurated and often drying yellowish; anthers copiously pilose with curly hairs; stigma a capitate cone of hairs. Legume oblong, compressed but apparently little compressed between the seeds, with numerous, parallel transverse lamellae to 5 mm tall, 4-5 mm apart, copiously hispid with brownish stinging hairs; seeds not seen.
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