Plants perennial herbs, with deep, woody taproots, these usually thickened toward the tip, either strongly enlarged and turnip-shaped or forming a knobby and sometimes few-branched caudex. Stems solitary or few to several and clustered, erect or loosely ascending from a spreading base (occasionally nearly absent in P. esculentum), branched or unbranched, unarmed, variously hairy, sometimes also minutely gland-dotted, the lowest nodes sometimes leafless or with small, scalelike outgrowths. Leaves alternate (sometimes appearing in a basal cluster in P. esculentum), palmately 3–5(–7)-foliate, short- to long-petiolate, the petiole more or less jointed at the base. Stipules mostly lanceolate to narrowly elliptic or linear (those at the lowest, often leafless nodes usually longer, broader and partly fused), attached at the base, persistent or shed early; stipels absent. Leaflets elliptic to lanceolate, ovate, or obovate, rarely nearly linear, all those of a leaf more or less similar, mostly angled or slightly tapered at the base, variously shaped at the tip, the margins entire, hairy, the surfaces variously hairy, the upper surface sometimes also gland-dotted, the venation pinnate (but sometimes mostly obscured by the pubescence). Inflorescences axillary, dense spikes or spikelike racemes (sometimes reduced to dense clusters in P. tenuiflorum), relatively short, but usually becoming more elongate with age, mostly long-stalked, the bracts lanceolate to ovate, hairy, more or less persistent, the flower stalks absent or 1–2(–4) mm long; bractlets absent. Calyces 2.5–16.0 mm long at flowering, becoming somewhat enlarged at fruiting, the tube bell-shaped, sometimes asymmetrically so (appearing slightly pouched on 1 side), shorter than to longer than the lobes, 5-lobed (the upper pair sometimes fused toward the base), the lobes ascending at flowering, the lowermost lobe somewhat longer than the others. Corollas papilionaceous, usually blue to purple or lavender, rarely white (the keel often darker at the tip), usually fading to cream-colored or tan, the banner with the expanded portion sometimes having contrasting markings toward the base, oblanceolate to obovate, tapered to a stalklike base but with a pair of small basal auricles, rounded to broadly and bluntly pointed at the tip, occasionally shallowly notched, abruptly curved or bent upward at about the midpoint, the wings slightly shorter than to about as long as the banner, the expanded portion angled or curved over the keel, asymmetrically oblong to oblong-oblanceolate, with a small auricle at the base, stalked, the keel shorter than the other petals, fused to the wings toward the base, short-stalked, boat-shaped, oblong to oblanceolate, only slightly curved upward, rounded at the tip. Stamens 10, 9 of the filaments fused at flowering and 1 of the filaments free above the midpoint, the free portion of alternating longer and shorter filaments, the anthers in 2 alternating series, those of the longer filaments attached at the base and those of the shorter series attached toward the midpoint, all yellow. Ovary short, ellipsoid to ovoid, very short-stalked, hairy toward or at the tip, the style slender, often strongly curved, hairy toward the base, sometimes also with an inconspicuous ring of short hairs at the tip, the stigma small and terminal. Fruits modified legumes, elliptic to oblong or oblong-oblanceolate, flattened, sessile or nearly so, short-tapered to a beaked tip, the surfaces leathery or papery, glabrous or hairy, sometimes gland-dotted, more or less smooth (not wrinkled), indehiscent or dehiscing irregularly transversely below the midpoint, 1-seeded. Seeds oblong-elliptic to somewhat kidney-shaped in outline, somewhat flattened, olive green to reddish brown, sometimes with darker streaks or mottling, smooth, somewhat shiny. Twenty-three species, North America.

Pediomelum often has been included in Psoralea L., along with Orbexilum and Psoralidium, but Grimes (1990) recognized it as separate genus based on the palmately compound leaves, persistent bracts, pouched calyces, and the unusual dehiscence pattern of the fruits via a transverse rupture. The present treatment also includes P. tenuiflorum, a species placed by Grimes in another segregate genus, Psoralidium because of its indehiscent fruits. For more discussion on this slightly expanded circumscription of Pediomelum, see the treatment of P. tenuiflorum below.