Herbs, annual, 5–30 cm, glabrous throughout or puberulent at base. Stems erect, branched from base and throughout, bushy. Leaves alternate, spreading to ascending; stipular glands absent; blade linear, 10–28 × 1–1.5 mm, margins entire or sparsely toothed on distal leaves, not ciliate, apex acute. Inflorescences dense panicles. Pedicels 2–7 mm. Flowers: sepals tardily deciduous, lanceolate, 5–9 mm, margins narrowly scarious, conspicuously glandular-toothed, apex acute to acuminate; petals yellow, obovate, 6–11 mm; stamens 4–6 mm; anthers 0.4–0.8 mm; staminodia absent; styles connate nearly to apex, 2.5–4 mm; stigmas capitate. Capsules ovoid, 3.5–4.4 × 2.7–3.5 mm, apex obtuse, dehiscing into 5, 2-seeded segments, segments persistent on plant, false septa complete, proximal part membranaceous, not terminating in loose fringe, distal part cartilaginous, margins not or only minutely ciliate. Seeds 2.6–3.1 × 1–1.3 mm. 2n = 30.