Japan Flora: Perennial, slightly pubescent while young; stems erect to ascending, angular, 60-100 cm. long, branched above; leaves short-peti- oled, the stipules dentate or bifid, the leaflets 2, coriaceous to chartaceous, ovate to broadly lanceolate, 4-7(-10) cm. long, (8-)15-40 mm. wide, gradually acute, sometimes subobtuse; racemes 2-4 cm. long, one-sided, the peduncles variable in length, to 6 cm. long, or absent, sometimes branched at base; flowers bluish purple, 12-15 mm. long, the bracts inconspicuous; calyx-teeth short; legumes broadly lanceolate, 2.5-3 cm. long, 5-6 mm. wide, nearly sessile, glabrous. June-Oct. Thickets and grassy places in lowlands and low mountains.
Hokkaido, Honshu, Shikoku, Kyushu; very common and variable. e. Siberia, China, Korea, and Sakhalin.
f. angustifolia Makino. Phase with narrow linear leaflets.
Japan Flora: Resembling V. unijuga, but the bracts narrowly ovate to lanceolate, acuminate, sometimes toothed, 3-8 mm. long; leaves thinner, the leaflets acuminate. June-Aug. Mountains.