Herbs annual, sparsely glandular pubescent. Stems 45--50 cm tall, diffuse and decumbent, quadrangular, sparsely branched at base. Basal leaves petiolate, ovate, small; middle cauline leaves with petiole 2--4 cm; leaf blade oblong-ovate, 2--4 × 2--3(--4) cm, both surfaces sparsely pubescent, base cordate, apex acuminate; distal leaves shortly petiolate, small, sessile to semiclasping. Flowers in terminal, sparse cymes; bracts ovate, herbaceous. Pedicel 2--3 cm, slender, with white soft hairs. Sepals 5, lanceolate, 5--8 mm, outside sparsely pubescent, apex acute. Petals slightly longer than sepals, 2-cleft nearly to base. Stamens 10, slightly shorter than sepals. Styles 3, linear. Capsules ovoid, 1.5--2 × as long as persistent sepals. Seeds numerous, brown, suborbicular, ca. 1 mm in diam., tuberculate. Fl. May--Jun, fr. Jun--Jul. 2n = 26.