Slender, nearly glabrous annual. Stems erect, simple or few-branched below, 3–20 cm. Leaves: basal petiolate with ovate blade 2–5 mm long; cauline linear, 3–15 mm long. Inflorescence an erect, terminal, several-flowered cyme. Flowers: sepals narrowly lanceolate, 3-veined, glabrous, 3–5 mm long; petals 1–2 mm long or absent; stamens 3 to 5. Capsules 2–3 mm long, opening by 3 slits (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).