Glabrous annual. Stems ascending, branched, 20–50 cm. Leaves opposite, compound; leaflets 2, oblong, 1–2 cm long. Flowers: sepals oblanceolate, ca. 6 mm long; petals yellow, separate, barely exceeding the sepals; ovary superior with 5 carpels; stamens 10; filaments basally winged. Fruit a pendent, oblong, many-seeded capsule 2–3 cm long (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).