Annual herb 5–15 cm high. Stem usually simple, sometimes branched at inflorescence region. Leaves sessile, ovate to broadly elliptic-ovate, 2.5–5.1(–8) mm long, 1.5–4 mm wide, acute. Flowers usually solitary; pedicels 5.5–7.5 cm long, usually equal to or longer than stem; bracts elliptic-lanceolate, 2.5 mm long, ± 0.5 mm wide, acute. Flowers 5-merous, heterostylous, pale creamy to white. Calyx almost divided to the base; segments lanceolate, 4–6 mm long, ± 1.5 mm wide, acuminate, margins hyaline; wing ± 0.3 mm wide at the middle. Corolla tube cylindrical to funnel-shaped, ± 7.5–9 mm long, scabrid, conspicuously swollen at anthers; lobes obovate, 3–4 mm long, 2–2.6 mm wide, apiculate, scabrid on outside. Short-styled form: filaments ± 2 mm long; anthers free, 0.7–1 mm long; apical gland lanceolate, 0.8–1.5 mm long; basal glands 2, minute, globose, shortly stipitate; style ± 0.9 mm long; stigma clavate, 1–1.2 mm long, papillate. Long-styled form: filaments none to extremely short; anthers 1 mm long, fused at their sides, surface scabrid-denticulate; apical gland ± 0.9 mm long, smooth, basal glands 2, stipitate; style ± 2.5 mm long; stigma clavate, 1.2 mm long, papillate; ovary obovoid to oblong, ± 2 mm long, ± 1.2 mm diameter. Capsule ellipsoid, 3–5.5 mm long, 2–3.5 mm diameter. Seeds ± 0.3 mm in diameter, surface pitted.
