Taprooted annual. Stems erect, usually unbranched, stout, with short glandular and long eglandular hairs, 20-35 cm tall. Lvs densely hispid, green; basal lvs oblanceolate-spathulate, acute, 5-8 × 1-3 cm; stem lvs becoming linear-lanceolate, very shortly connate, acute, 3-8 × 0.5-2 cm. Infl. a 3-10-flowered dichasium; pedicels 1-3 cm long; bracts linear-subulate, green. Fls ☿. Calyx with short glandular and short and long eglandular hairs, cylindric at flowering, ovoid at fruiting, contracted at mouth, 18-23 mm long, 10-veined; teeth linear-acuminate, erecto-patent. Petals pink above, yellowish beneath, inrolled by day, spreading at night, deeply divided; claw not lobed; coronal scales oblong, obtuse, c. 2 mm long. Styles 3, erect, c. 5 mm long. Capsule ovoid, slightly exserted, 10-14 mm long; teeth 6; carpophore c. 2 mm long. Seeds dull brown, reniform, papillate, c. 1.3 mm long.