Herbs perennial, robust, erect, with fleshy stolons 1-12 cm, extending underground and terminating in thickened buds. Stems 40-120(-200) cm tall, simple or sparsely branched, densely glandular and strigillose throughout, with faint raised strigillose lines decurrent from margins of petioles. Leaves subsessile above, lower ones with petioles 1-6 mm; cauline blade narrowly ovate to lanceolate, 3.5-8(-11) × 1.5-4(-4.5) cm, subglabrous with densely strigillose margin and midvein, base broadly cuneate to subrounded, margin sharply serrulate with 28-42(-60) teeth per side, apex acute. Inflorescence erect, congested; flowers erect. Sepals 5-8 mm. Petals rose-purple, 7-15(-18) mm. Stigma capitate to broadly clavate, entire. Capsules 7-11 cm, strigillose, glandular; pedicels 0.7-1.5 cm. Seeds dark brown, 0.8-1.2 mm, coarsely papillose, with short chalazal collar; coma white, detaching easily. Fl. May-Aug, fr. (May-)Jul-Sep. 2n = 36*.