Scrambling perennial; stems glabrous, angled, broadly winged. Lvs glabrous; tendril branched in upper lvs, sometimes simple in lower lvs; leaflets in 1 pair, usually lanceolate to linear, rarely narrowly elliptic, narrowly acute to acuminate, 50-130 mm long; veins parallel; stipules lanceolate to linear, with 1 narrow basal lobe, < 1/2 as wide as stem (c. 1-3 mm wide), (5)-10-20 mm long. Infl. > lvs, (2)-5-8-flowered; pedicels 4-10 mm long. Calyx glabrous, slightly or not gibbous at base; calyx teeth unequal, narrowly triangular, < tube. Corolla purple-pink, 13-17 mm long. Pod glabrous, brown, 8-15- seeded, 40-70 mm long; seeds reticulate-rugose; hilum ?-1/2 of circumference.