Annual to perennial herbs. Hairs glandular and/or eglandular or 0. Lvs opposite, exstipulate, ovate to linear to spathulate. Infl. a lax to capitate dichasium, sometimes a panicle; bracts leaflike; epicalyx 0. Calyx cylindric or oblong, 5-veined, 5-toothed, with green commissures between the veins. Petals 5, white or pink, clawed or narrowed to base, entire to 2-fid; coronal scales usually present. Stamens 10. Styles 2. Fr. a cylindric to ovoid capsule dehiscing by 4 teeth; carpophore short. Seeds reniform, compressed, not winged.