Description from Flora of China
Manulea indiana Loureiro, Fl. Cochinch. 2: 386. 1790; Adenosma capitatum (Bentham) Bentham ex Hance; Pterostigma capitatum Bentham.
Annuals, 19-60(-100 or more) cm tall, densely hairy. Stems erect, branched. Petiole 2-6 mm; leaf blade ovate to narrowly elliptic, 1.5-4.5 X 0.5-1.2 cm, densely glandular hairy, abaxially villous along veins and brown when dry, adaxially villous and blackish when dry, margin serrate, apex obtuse. Inflorescences globose to cylindric spicate, 0.7-2 X 0.7-1.1 cm, dense; bracts narrowly ovate, forming an involucre at base of spikes. Flowers sessile. Bracteoles linear, 3-4 mm. Calyx 4-5 mm; lobes narrowly ovate to oblong-lanceolate, 2-3 mm, apex acuminate. Corolla pale purple to dark blue, ca. 6 mm; throat hairy; lower lip lobes equal, suborbicular, ca. 1 X 1-1.2 mm; upper lip retuse to 2-lobed. Anterior anthers with 1 locule fertile; posterior anthers with both locules fertile. Ovary narrowly ovoid. Capsule ovoid, ca. 3 mm, 2-grooved. Seeds yellow. Fl. and fr. Sep-Nov.
The SE Asian Adenosma microcephalum J. D. Hooker is similar to A. indianum, differing only by the spikes which are not involucrate. Adenosma microcephalum has been reported
from Guangdong (Loufushan), but because we have not seen any specimens of this species, it is not included.
Barren lands, dry mountain sides, along streams, fields; low elevations. Guangdong, Guangxi, Hainan, Yunnan [Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Philippines, Sikkim, Thailand, Vietnam].