Stems simple, erect, much-branched, rigid, terete, up to 1 m. or sts 2 m. tall; branches reddish, glabrate to sparingly pubescent. Lvs sessile or nearly so, rather distant, opp. except in floral region. Lamina ovate-to narrow-lanceolate, attached by broad base, subpatent, 35-65-(90) × 8-15 mm., membr., glab. except sts on margins and main nerves; margins closely to rather remotely denticulate. Infl. us. ample; fls ∞, ± 5 mm. diam.; calyx deeply divided, ± pubescent to pilose, lobes narrow-lanceolate, ± 4 mm. long; petals magenta or paler, 5-6·5 mm. long, shortly 2-lobed. Capsules 50-60-(75) mm. long, finely and evenly pubescent to almost pilose; peduncles ± 6 mm. long, pubescent. Seeds papillose.

Erect perennial herb 20-80 cm tall, in late summer producing elongated leafy stolons above or on surface of ground, these not terminating in distinct rosettes; stems strigillose above, glabrous below, with the hairs concentrated on raised lines running down from petiole margins. Lvs mostly opposite, alternate in the infl., subsessile and often somewhat decurrent, 1.5-10 × 0.4-1.8 cm, lanceolate to narrowly ovate, green or bluish green, strigillose on midrib and veins below, otherwise glabrous, denticulate; base rounded to amplexicaul; apex obtuse. Infl. erect, with mainly strigillose hairs. Fls erect. Ovary 1.2-3.8 mm long, strigillose. Floral tube 0.8-1 mm deep, with a conspicuous rim of dense long hairs inside, strigillose with a few glandular hairs outside. Sepals 2.5-4.5 × 1-1.3 mm, strigillose, somewhat keeled. Petals rose-purple, 3.5-6 × 1.8-3 mm. Filaments of the longer stamens 2-2.2 mm long. Style white, 2.5-3.5 mm long, glabrous; stigma clavate, 1.5-2 mm high. Capsule strigillose, 4-7 cm long; fruiting pedicel 0.4-1.6 cm long. Seeds 0.8-1.0 × 0.35-0.4 mm, obovoid, coarsely papillose.