Annual or biennial. Stems erect, 7–50 cm, copiously branched. Basal leaves petiolate, oblanceolate, pinnatifid, withering early. Stem leaves 12–50 mm long, dentate, becoming linear and entire above. Vestiture of small simple hairs. Flowers white; petals ca. 1 mm long or lacking; stamens 2. Fruit narrowly elliptic, glabrous or sparsely short-hairy, 2.5–3 mm long, narrowly notched; style lacking; pedicels spreading, puberulent, 2–4 mm long. (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
In Montana we have varieties
ramosissimum and
bourgeauanum (Thell.) Rollins