27. Crotalaria mairei H. Léveillé, Bull. Acad. Int. Geogr. Bot. 25: 49. 1915.
头花猪屎豆 tou hua zhu shi dou
Herbs, perennial, ascending to erect, 10-60 cm tall. Stems many from base, terete, densely silky pilose. Stipules acicular, 1-2 mm, persistent or caducous. Leaves simple; petiole 1-4 mm; leaf blade lanceolate, oblong-lanceolate, or rarely oblanceolate, 1.5-3 × 0.5-1.5 cm, abaxially densely brown pilose, adaxially glabrous or very sparsely pilose, base cuneate, apex shortly acuminate to rounded and cuspidate. Racemes terminal, headlike, less than 5 cm, 10-20-flowered; bracts linear to linear-lanceolate, 4-8 mm. Pedicel ca. 2 mm or ca. 5 mm when flowers arranged laxly on branch tip and not headlike; bracteoles inserted at base of calyx, similar to bracts. Calyx 2-lipped, 1-1.3 cm, deeply divided, densely brown pilose or pubescent; lobe apices long acuminate; abaxial lobes lanceolate; adaxial lobes oblong-ovate, ca. 3 mm wide. Corolla deep purple or purplish blue, ± as long as calyx; standard ovate to suborbicular, 0.8-1.3 cm, abaxially pilose near tip, base with 2 appendages, apex obtuse to retuse; wings oblong, 0.8-1.3 cm; keel ovate, ± sharply angled near base, margins proximally woolly, apex extended into a long straight twisted beak. Ovary subsessile. Legume cylindric, ca. 1 cm, included in or slightly exserted beyond calyx, 10-15-seeded, glabrous. Fl. Sep-Nov, fr. Dec-Feb.
Montane grasslands; 300-3000 m. Guangxi, Guizhou, Sichuan, Xizang, Yunnan [India, Myanmar, Nepal, Sri Lanka].