Perennial from a tightly- to loosely-branched caudex. Stems erect, 1–80 cm, glabrate to sericeous. Leaves basal and cauline; lower petioles 6–30 cm long; leaflets 7 to 11, strigose to sericeous beneath, glabrous to sericeous above, 3–10 cm long with acute tips. Racemes solitary, dense, higher than the leaves, 2–25 cm long. Flowers dark blue; calyx tube strigose to sericeous, 1–2 mm long, not spurred; upper lip 3–6 mm long, equal to the lower; banner glabrous, 8–12 mm long, reflexed >50°, usually with a yellow center; wings 9–15 mm long. Legume 10–25 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Montana plants are varieties burkei
(S. Wats.) C.L. Hitchc. and humicola
(A. Nels.) Barneby.