Standard elliptic, pale violet inside and marginally outside, yellowish-brown with deep brown veins medially outside, glabrous; wings deep violet, shorter than the keel; keel 1.8–2.1 cm long, angular, sharply rounded near the base with a long practically straight beak.
Perennial herb, with 1–many stems from a horizontal woody rootstock; stems erect, up to 1.5 m tall, simple or branched above, 4-angular, strongly ribbed, glabrous.
Racemes laxly 6–16-flowered; bracts linear-subulate, 1.5–3 mm long; bracteoles variously inserted on the pedicel, smaller.
Calyx 7–8 mm long, glabrous; lobes narrowly attenuate-triangular, nearly twice as long as the tube, becoming reflexed.
Young legumes shortly stipitate, oblong-ellipsoid, sparsely pubescent.
Seeds not seen.