Herbs perennial. Stems 30-60 cm, bristly to subglabrous. Basal leaves smaller; petiole of upper leaves 1-6 cm; upper leaf blade ovate to ovate-lanceolate, 2.5-6 × 1.5-4 cm, adaxially sparsely appressed, minutely hispid, especially near margin, base cordate, margin dentate-serrate, apex acute to cuspidate-acuminate. Verticillasters 8- or 9-flowered; floral leaves similar to stem leaves but subsessile; bracts linear, ca. 1/6 as long as calyx. Calyx campanulate, 9-13 × 2-3 mm, base sometimes purple red, sparsely bristly, minutely hispid; teeth lanceolate, as long as tube, awned, margin ciliate. Corolla yellowish or dirty white, 2-2.5 cm; tube at least as long as calyx, 2-2.5 mm in diam., pubescent, hairy annulate inside, throat dilated; upper lip obovate, 7-10 × 6 mm, obtuse; lower lip 1-1.2 cm, middle lobe 4-6 × 3-4 mm, obreniform, margin ciliate; lateral lobes circular, ca. 2 mm, with a subulate tooth ca. 1 mm. Anthers black-purple, villous. Nutlets dark gray, narrowly ovoid, triquetrous, 3-3.5 × 1.5-1.7 mm, glabrous, tuberculate. Fl. Jul-Sep, fr. Aug-Oct.