单蕊黄耆 dan rui huang qi

Astragalus luteus Ulbrich.

Plants 20-60 cm tall, with mostly white hairs 0.4-1 mm. Stems at base 1.5-3 mm thick, glabrous or nearly so. Leaves 7-12 cm, nearly sessile; stipules 8-16 mm, often reflexed, sparsely ciliate; rachis glabrous or nearly so; leaflets in (4-)6-8 pairs, narrowly elliptic to narrowly ovate, 1.2-3.5 × 0.5-1.3 cm, abax­ially gray-green and sparsely hairy, adaxially dull green and glabrous, apex rounded or shortly acuminate and minutely mu­cronulate. Racemes 1-sided, loosely many flowered; peduncle 6-12(-15) cm, erect, glabrous; bracts greenish, narrowly ellip­tic, 6-10 mm, white and black ciliate, apex acute. Calyx greenish to reddish, campanulate-tubular, 8-10 mm, tube gla­brous or sometimes sparsely black hairy; teeth subulate, (2-)3-4 mm. Petals yellow; standard widely elliptic to widely obovate or nearly orbicular, (10-)12-13 × 5-6 mm; wings (10-)11-12 mm; keel 10-11 mm. Stamen tube closed, monadelphous. Leg­umes with a white hairy stipe 5-6 mm, inflated ellipsoid, ca. 15 mm, ca. 6 mm high and wide, keeled ventrally, flattened dor­sally; valves thinly membranous, loosely covered with as­cending short white and black hairs.

● Gansu, Qinghai, Shaanxi, Sichuan, Yunnan.