Flora of North America species comparison

prostrate, ascending, or erect, usually much-branched, pubescent.

10–50 cm, hairs antrorse.

alternate, odd-pinnate;

stipules present, persistent, amplexicaul, papery or membranous, striate, broadly ovate-elliptic;

sessile or petiolate, petiole to 5 mm;

leaflets 3, stipels absent, blade margins entire, apex mucronate, lateral veins parallel, unbranched, extending to margins, surfaces glabrous except abaxial midrib and margins.

stipules 3–5 mm, acute to acuminate;

leaflets dimorphic, proximal blades obovate, distals narrowly obovate, abaxial surface sparsely pubescent on midrib and margins, hairs appressed or ascending, white, apex retuse or emarginate;

terminal leaflet blade 6–13 × 3–9 mm.

proximal bracts minute, subulate;

second proximal blade elliptic, 0.8 mm, apex acute;

distal blades broadly ovate, 1.6–1.8 mm, 3-veined.

1–4-flowered, axillary, reduced pseudoracemes, simple or singly branched, subtended by prophyll;

prophyll similar to bract, 1 or 2, each persistent at base of axis, proximal one at base of peduncle, second proximal one at base of branch;

bracts present, persistent, 4 at base of calyx, proximal 2 lateral, distal 2 opposite, larger than proximal bracts, shorter than calyx.

chasmogamous flower 1, cleistogamous flower 0 or 1;

prophylls 1 or 2, blades ovate, proximal one 0.5 mm, second proximal one 1 mm.

to 0.5 mm in cleistogamous flowers, 1–1.5 mm in chasmogamous; glabrous or sparsely puberulent.

chasmogamous and cleistogamous; chasmogamous flowers papilionaceous, 1 or 2;

calyx persistent, campanulate, broadly so in fruit, strongly leafy veined, lobes 5, lobes broad, subequal to tube, adaxial 2 partly or mostly connate;

corolla long-exserted from calyx, banner pink-purple, wings white, distinctly shorter than keel, keel purple apically;

stamens 10, diadelphous;

anthers dorsifixed;

disc present inside staminal tube;

ovary sessile, style glabrous; cleistogamous flowers indistinct, often absent, rudimental flower-bud, enclosed in calyx, 0–4.

legumes, sessile, ± flattened, elliptic or broadly ovate to ± globose, style apex early deciduous, indehiscent, reticulate, pubescent; chasmogamous legumes 1 or 2; cleistogamous legumes 0–2 at base, usually slightly smaller than chasmogamous.

elliptic, 2.5–3.5 × 1.5–2.5 mm, sparsely appressed-puberulent, less than 1/2 covered by persistent calyx;

apex rounded.

1, brown, compressed, orbicular or broadly ovoid;

hilum eccentric.

1.5–1.8 × 1.2 mm.

flowers 5–6 mm;

calyx 1.5–2 mm, glabrous.

flowers often absent, 0.5 mm.

= 10, 11.

= 20, 22.