Description from Flora of China
Plants perennial. Stems 35-55 cm, erect, glabrescent except for ± densely villous nodes. Petiole subequal to blade; leaf blade cordate-orbicular, 4-8 cm, mid stem blades largest, adaxially densely appressed villous, abaxially sparsely villous, densely glandular, margin crenate-serrate, apex rounded or acuminate with apical tooth enlarged. Verticillasters 2-flowered, widely spaced, in loose raceme-panicles; rachis densely glandular pilose; bracts caudate-acuminate, glandular pilose; upper bracts broadly ovate, 3-5 mm. Pedicel 3-5 mm. Calyx campanulate, 8-10 mm, 4-5 mm wide at mouth, ciliolate, 2-lipped to 1/3 its length, veins spreading glandular villous; upper lip entire, broadly ovate-triangular, apex short acuminate; teeth of lower lip ovate, apex long acuminate, 3-4 mm; fruiting calyx adaxially dilated, upper lip reflexed. Corolla purple, 3-4.5 cm, tube to 3 cm, adaxially gradually dilated to 1-1.5 cm wide at mouth, slightly curved upward, glabrous, pilose annulate inside; upper lip broadly ovate, 1-1.4 cm, curved upward at 45° from base; lobes circular, ciliolate, fine pilose abaxially; lower lip ca. 1.5 × as long as upper, middle lobe broadly obcordate, shallowly undulate, violet when dry. Connectives curved, 0.8-1.2 cm, finely pilose on joints, lower arms ca. 1/2 as long as upper. Immature nutlets chestnut brown, subglobose (specimens not seen).