Root tubers solitary or several in fascicles, lilac. Stems usually repent at base, ascending above, 5--10 cm tall, slender, much branched, with 2 lines of hairs, with dwarf shoots from leaf axils. Proximal leaves narrowly elliptic, 1.5--2.5 cm × 4--6 mm, base attenuate into a petiole, margin rough, apex acute. Middle and distal leaves: petiole 3--10 mm, sparsely pubescent; leaf blade ovate or broadly ovate, 1--2.5 × 0.6--1.5 cm, base cuneate, apex acute. Chasmogamic flowers solitary, terminal at stem apex; pedicel slender, sparsely pubescent; sepals 4, narrowly elliptic, ca. 3 × 1.5 mm; petals 4; stamens 8; ovary ovoid; styles 2. Cleistogamic flowers solitary in leaf axils of dwarf shoot; pedicel 5--20 mm, sparsely pubescent; sepals 4, narrowly elliptic; petals absent; stamens 2. Capsule with purple stains, ovoid, 3--4 mm, 4-valved. Seeds deep brown, subreniform, ca. 1.5 mm, tuberculate, apex of tubercles with one short hair. Fl. Jun--Jul, fr. Jul--Aug.