Slender biennial herb up to 30-(35) cm high. Stems glabrous, simple to much-branched at base. Stem lvs always opposite, glabrous, oblong to narrowly elliptic-obovate, usually obovate at base of stem, obtuse to acute, 1-veined, entire, (3)-5-12-(15) mm long; lvs subtending infl.-branches single or paired, similar to stem lvs but shorter, narrower and sometimes acuminate. Infl. of few to numerous fls in a diffuse compound dichasium; sepals elliptic, acuminate, glandular, ciliate, 2-3 mm long, slightly < or ± = to capsule; petals white, about 2× as long as sepals, 3.5-5 mm long; styles free to base. Capsule glabrous, globose, dehiscent, 2-3 mm diam.; seeds boat-shaped, shiny light brown, c. 1 mm long.