Description from Flora of China
Prunella indica N. Burman, Fl. Indica 130. 1768; Acrocephalus capitatus (Roth) Bentham; Ocymum capitatum Roth.
Herbs or sometimes subshrubs, to 1 m. Stems base sometimes prostrate, ± woody, much branched; branches slender, ascending, glabrous or sparsely villous on 2 sides. Petiole 2-7 mm; leaf blade lanceolate to ovate, 1.2-5 cm × 5-12 mm, herbaceous, adaxially subglabrous, abaxially sparsely glandular, sparsely minutely hispid on veins, base attenuate-decurrent, margin remotely serrate, apex obtuse. Verticillasters many flowered, overlapping, in globose or ellipsoid capitula; bracts sessile, rhombic-flabellate, ca. 3 mm, acute, concave, base densely villous outside, glabrous inside. Calyx ca. 1.5 mm, pilose; upper lip entire, long; lower lip 4-toothed, teeth subulate, ciliate; fruiting calyx dilated, tubular, to 3 mm. Corolla white to purple-red, ca. 2 mm, slightly exserted. Stamens included, anterior 2 longer. Nutlets dark brown, ovoid, ca. 1 mm. Fl. Sep-Oct, fr. Nov.
Rice paddies, forest margins, streamsides, bamboo forests; 100-1800 m. Guizhou, Yunnan [India, Indonesia, Laos, Malaysia, Myanmar, Philippines, Thailand, Vietnam].