Crotalaria sessiliflora L.

Herbs, annual or short-lived perennial, erect, 30-100 cm tall. Stems often branching from lower parts, terete, densely coarsely hirsute. Stipules linear, 2-3 mm, persistent or cadu­cous. Leaves simple; petiole nearly absent; leaf blade variable in shape, usually linear to linear-lanceolate, 3-8 × 0.5-1 cm, abaxially densely silky pubescent, adaxially glabrous, base attenuate, apex acuminate. Racemes terminal or leaf-opposed or densely congested and headlike on branch apices, few to many flowered or flowers solitary in axils; bracts linear-lanceolate, 4-6 mm. Pedicel ca. 2 mm; bracteoles inserted at base of calyx tube, similar to bracts. Calyx 2-lipped, 1-1.5 cm, conspicuously long brownish pilose; abaxial lobes lanceolate to triangular-lanceolate, to 2.5 mm wide, connate for ca. 1/4 of length; adax­ial lobes ca. 4 mm wide, joined for ca. 1/3 length, apices long acuminate. Corolla blue to purplish blue or pale yellow, slightly shorter than calyx; standard oblong, 7-10 × 4-7 mm, abaxially sparsely strigose along midvein, base with 2 appendages, apex obtuse to retuse; wings oblong to linear-oblong, shorter than standard; keel ± as long as standard, bent sharply below middle, adaxial margin proximally woolly, apex extended into straight twisted beak. Ovary subsessile. Legume dark with age, cylin­dric, ca. 1 cm, ± included in calyx, 10-15-seeded, glabrous. Fl. May-Nov, fr. Oct-Feb.

Grassy places in lowland areas of central and southern Japan. Open grassy places at elevations of 200-2,800 metres in Nepal. Valley grasslands, along trails; at elevations from 100-1,600 metres in China.

Can be grown by seedlings. Seeds needs soaking.