Annuals, 5-10 cm tall. Stems erect, glabrous or puberulent. Leaves 4, whorled below inflorescence; leaf blade oblong to oblong-lanceolate, 3-10 mm, glabrous, base attenuate into short petiole, margin entire. Racemes lax, twisting; bracts alternate, much smaller than leaves, oblanceolate to sublinear, margin entire. Flower 1 in bract axil. Pedicel long, thin, 3.5-12 mm, 2-5 X as long as bract, curved downward after flowering. Calyx 4-lobed, 2-3 mm, parted to base; lobes linear-lanceolate, subglabrous, midrib conspicuous. Corolla blue, rotate, 1-3 mm in diam. Capsule reniform, strongly compressed, 1.5-2 X 2.5-3 mm, parted to 2/3 length, glabrous, notch angle ca. 90°. Style 0.5-0.7 mm. Seeds 8-12 per capsule, oblong, 0.7-1.3 X 0.5-0.7 mm; seed coat dorsally slightly wavy. Fl. Apr-Jun.