Herbs annual, 10--15 cm tall. Stems simple or few branched, erect, pubescent, mixed with glandular hairs distally. Leaves ovate-lanceolate, 1--3 cm × 2--5 mm, pilose, base amplexicaul, margin ciliate, apex acuminate. Dichasium terminal, somewhat lax; bracts leaflike, ovate-lanceolate, pilose. Calyx ovate, 1--1.2 cm × ca. 3.5 mm, strongly inflated in fruit, abaxially glandular pubescent, margin membranous. Petals oblong-obovate, ca. 1.5 × as long as calyx, apex retuse. Stamens 10. Styles 5. Capsule erect, conical-cylindric, ca. 1.5 × as long as calyx, teeth flat. Fl. May--Jul.