Flora of North America species comparison

twining or trailing, densely pilose or hirsute, hairs spreading, not uncinate, glabrous, or glabrescent.

alternate, odd-pinnate, pulvinate;

stipules present, persistent, not produced proximal to insertion;

petiolate;

leaflets 3, stipels present, blade margins entire, surfaces pubescent or glabrous.

stipules ovate-lanceolate, 4–8 × 4 mm;

petiole 6–8 cm;

rachis 2–2.5 cm;

stipels persistent, awl-shaped, minute;

leaflets membranous to papery, blades broadly ovate to deltate, lateral ones asymmetric, 3–9 × 2–7.5 cm, base cuneate to truncate, apex acuminate, surfaces glabrous.

2–10-flowered, axillary, pseudoracemes, rachis with glandular, swollen nodes, 1 or 2 flowers per node;

bracts present;

bracteoles deciduous, ovate, shorter than calyx tube.

to 40 cm, flowers clustered at 2–5 nodes;

bracts persistent, minute.

mostly shorter than calyx tube.

1–2 mm;

bracteoles 3 mm.

papilionaceous;

calyx campanulate, lobes 4, ca. 1/4 as long as tube;

lower and lateral lobes triangular to lanceolate, equal to or 2 times longer than tube, upper lobes triangular, broad and emarginate;

petals distinct;

corolla light to deep purple or deep lilac;

banner expanded at anthesis, usually hooded;

wings obovate, conspicuously projected beyond distal bend of keel;

keel beak sigmoid to coiled, distally flaplike, very tightly coiled distally, projected downward, tip not hidden by wings, not folded back distally;

stamens 10, diadelphous;

anthers sub-basifixed, oblong;

ovary straight, nectary disc at base;

style distally thickened with pollen brush distal to stigma;

stigma apical to slightly introrse or laterally extrorse.

light to deep purple, 2–3 cm;

calyx 4–7 mm, puberulent, lower lobes triangular, 3 mm, lateral lobes lanceolate, slightly curved, upper lobe obtuse;

banner oblong, 2–2.5 × 2 cm;

wings obovate, 2–2.2 × 1–1.5 cm;

keel beak sigmoid;

vexillary stamen geniculate at base.

legumes, sessile, compressed, narrowly linear or slightly curved, sometimes long-beaked at apex, dehiscent, puberulent or thinly strigose.

narrowly linear to slightly curved, 6–14 × 0.5 cm, puberulent.

1–20, oblong to reniform, testa smooth.

13–17, oblong to oval-reniform, 3.5–4 × 2–3 mm.

, perennial, unarmed, base woody;

taproot woody.

3–7 m. Stems twining or trailing, hollow, striate, hirsute, hairs sometimes retrorse.