Annual, glabrous, glaucous, 15-60 cm. Stems erect, branched in upper part. Leaves 5-10 x 0.5-4 (-5) cm., radical oblong or lanceolate, tapering at base, upper ovate, clasping or connate at base. Inflorescences paniculate, of loose, spreading dichasial branches. Bracts narrowly lanceolate, acute, green to almost membranous, 1-nerved. Pedicels mostly as long as or longer than calyx. Calyx 1-1.7 cm., oblong to spindle-shaped, ovoid in fruit, glabrous, whitish-green between the 5 prominent ribs; teeth short, ovate-triangular or lanceolate, scarious at margin and often at apex. Petals 1.5-2.2 cm., pink ; limb short, obovate, entire or irregularly dentate or notched; claw long, exserted or not. Styles 2. Capsule 0.7-1 cm., ovoid or subglobular, with very prominent ribs extending into wings. Seeds about 2 mm. in diam., subglobular, black, finely tuberculate. Fl. February-May.