Annuals 10-15 cm tall. Stems erect, branched, glabrous. Basal leaves withered at anthesis. Stem leaves with petiole 2-3 mm, base broadened; leaf blade linear, 1-3 cm × 1-3 mm, apex acuminate, midvein indistinct. Inflorescences axillary or terminal clusters. Flowers sessile or subsessile, 5merous. Calyx tube with pale blue streaks, narrowly obconic, membranous, 6-8 mm; lobes linear, 7-12 mm, unequal, herbaceous, midvein indistinct. Corolla pale blue, with blackish streaks, broadly tubular, 2.5-3.2 cm; lobes ovate, 4-5 mm, margin entire, apex acute; plicae oblong, 2-2.5 mm, margin entire, apex obtuse to subtruncate. Stamens inserted at basal part of corolla tube, unequal; filaments 0.8-1.5 cm; anthers narrowly ellipsoid, 1-1.5 mm. Style linear, 3-4 mm, much shorter than ovary; stigma lobes linear. Capsules narrowly ellipsoid, 1.1-1.3 cm; gynophore to 4 cm. Seeds brown, ellipsoid to subglobose, 0.5-0.7 mm. Fl. and fr. Aug-Nov.