Plectranthus rosthornii Diels, Bot. Jahrb. Syst. 29: 562. 1900; Rabdosia rosthornii (Diels) H. Hara.

Herbs perennial. Stems 60-120 cm, purplish, densely puberulent. Leaves opposite; petiole 0.5-5 cm; leaf blade broadly ovate to subcircular, 4-11 × 2.5-7 cm, ± membranous, adaxially sparsely fine setulose, sparsely glandular, veins densely puberulent, base abruptly decurrent, margin crenate-serrate, apex acuminate, veins 4- or 5-paired. Panicles narrow, terminal and axillary, 5-15 cm; cymes widely spaced, pedunculate, 3(-5)-flowered. Pedicel 2-5 mm. Calyx broadly campanulate, to 2.5 × 3 mm, scattered glandular, veins and margins sparsely pubescent, obviously 2-lipped to middle or below; upper lip teeth short triangular, lower lip teeth narrowly triangular; fruiting calyx dilated to 6 mm. Corolla purplish white to purple-blue, to 5.5 mm, sparsely puberulent, glandular, tube ca. 2 mm, upper lip ca. 2 mm, lower lip ca. 3.5 mm. Stamens and style included or slightly exserted. Nutlets yellowish brown, ovoid, ca. 1.3 mm, glabrous, glandular. Fl. Aug-Sep, fr. Sep-Oct.

* Open slopes; 500-2300 m. Guizhou, Sichuan, Yunnan.