Flora of North America species comparison

erect to decumbent or prostrate, young stems glabrous or sparsely to densely pubescent, with or without glandular hairs.

alternate, odd- or even-pinnate;

stipules present, peltate and appendiculate proximal to point of attachment or attached at base and not appendiculate;

petiolate;

leaflets 5–80, alternate or subopposite, blades subsessile, pulvinate, sometimes sensitive to light and touch, margins entire or ciliate-denticulate, surfaces glabrous or pubescent.

1–15-flowered, axillary [terminal], usually racemes, sometimes fascicles (in A. villosa var. villosa), rarely solitary flowers, [panicles];

bracts present, usually stipulelike, smaller;

bracteoles paired at base of calyx.

papilionaceous;

calyx campanulate, lobes 5, subequal or bilabiate and abaxial lip 3-parted and adaxial lip 2-parted;

corolla yellowish, sometimes with red or purplish markings, keel acute, included, bent, or curved;

stamens 10, diadelphous, 5 + 5 or filaments forming sheath, splitting adaxially;

anthers usually dorsifixed, sometimes basifixed;

style glabrous;

stigma terminal, capitate or minutely penicillate.

loments, sessile, gynophore present, compressed, straight or curved, pubescent;

segments (1 or) 2–18, each 1-seeded, joints between seeds sometimes poorly developed, proximal segment dehiscent or indehiscent, sometimes continuous with gynophore.

1, reniform, smooth, sublustrous;

hilum lateral, circular.

= 10.