voluble, retrorsely-hispid, or rarely glabrescent; leaflets varying from ovate to lanceolate; peduncles 2–4-flowered at the summit; calyx tubuloso-campanulate, the 5 segments acuminate, somewhat longer than the tube; carina obliquely circularly incurved, spurred at one side. The herbaceous, voluble stem several feet long, the petioles and peduncles rough, with rigid, reversed, foxy hairs, rarely becoming subglabrous. Leaflets extremely variable in shape and length; sometimes ovate, 1 1/2–2 1/2 inches long, 3/4–1 1/4 inch wide; oftener ovato-lanceolate, 4–5 inches long, 1/2 inch wide at base, tapering to an acute point; sometimes linear, 1–2 inches long, 2–3 lines wide; all green at both sides, membranous, sparsely hairy above, setose, especially along the veins beneath; reticulately veined. Peduncles 3–4–12 inches long, 2–4-flowered at the summit; pedicels minute. Vexillum broad, reflexed, 9–10 lines long, with a folded claw, the limb with inflexed ears at base. Carina broadly falcate, much curved at the point, nearly forming a complete circle, and having on one side above the middle a conical, prominent spur. Legume sessile, linear, straight, hispid, 3–4 inches long, 2 lines wide. Flowers greenish-yellow, tinged with purple.
