Annual, 5-10 cm tall, glabrous or sparsely hairy, simple or branched, erect herbs. Leaves 3-10 x 1-3 mm, linear to linear-lanceolate, entire or so, in whorl of 4 at the base of inflorescence, occasionally cauline leaves only opposite, green on drying. Raceme 7-8 cm long, 5-20-flowered, lax, glandular hairy; peduncle 0.5-2 cm long; pedicel in fruit 4-15 mm long, capillary, patent, recurved at apex; bracts 2-3 mm long, linear, entire, alternate, glabrous or so. Calyx 4-lobed, connate at base in pairs, appearing as somewhat 2-lobed, 2-3 mm long; lobes linear-lanceolate, nearly glabrous, spreading, with 1 conspicuous vein. Corolla 1-3 mm across, white to bluish. Stamens inserted. Capsule 1.5-2 x 2.5-3.3 mm, obcordate, sinus ⅔ deep, strongly compressed, glabrous, lobes obtuse; style inserted, ± ½ as long as sinus. Seeds 8-12 per capsule, 1-1.3 x 0.5-0.7 mm, slightly concave on one side, dorsally slightly wavy and sparsely tuberculate, yellowish.