Description from Flora of China
Plectranthus excisus Maximowicz, Prim. Fl. Amur. 213. 1859; Amethystanthus excisus (Maximowicz) Nakai; Rabdosia excisa (Maximowicz) H. Hara.
Herbs perennial. Stems numerous, erect, 60-100 cm tall, semiwoody basally, sparsely pubescent. Petiole 0.6-6 cm, sparsely pubescent; blade of lower leaves broadly cuneate to ± truncate and abruptly attenuate-decurrent, margin coarsely dentate-serrate, adaxially strigose-hispidulous, densely pubescent on veins, abaxially glabrous, yellow glandular, sparsely pubescent on veins; stem leaves opposite, orbicular or orbicular-ovate, (4-)6-13 × (3-)4-10 cm, base cuneate, margin entire or 1- to few serrate, apex excised, apical tooth 4-6 cm; lateral veins 3- or 4-paired, elevated. Panicles terminal or axillary, 6-15 cm; cymes (1-)3-5-flowered, pedunculate, densely pubescent; floral leaves bractlike, ovate, to 5 mm; bracteoles linear, ca. 1 mm. Pedicel 1-2 mm. Calyx campanulate, ca. 3 mm, pubescent outside, glandular, 2-lipped to 2/3 its length; lower lip slightly longer than upper lip, to 1.8 mm; teeth narrowly triangular, acute; fruiting calyx slightly dilated, ca. 4 mm, obscurely 2-lipped, teeth subequal. Corolla purplish, purple, or blue, to 9 mm, puberulent outside, glandular, tube ca. 4 mm. Stamens and style included or slightly exserted. Nutlets brown, obovoid, ca. 1.5 mm, hairy, glandular. Fl. Jul-Aug, fr. Aug-Sep.
Grasslands, forest margins, forests; 500-1100 m. Hebei, Heilongjiang, Jilin, Liaoning, Shanxi [Japan, Korea, Russia].