Bot. Zhurn. (Moscow & Leningrad) 57: 1038. 1972
Plants usually sparsely to densely pubescent, rarely glabrescent, trichomes short-stalked, forked or subdendritic, these, sometimes, with simple, subsetiform ones. Stems unbranched or branched proximally, (0.4–)1.5–3(–5) dm, pubescent. Basal leaves soon withered. Cauline leaves petiolate or (distal) subsessile; petiole (0.1–)0.6–2(–3) cm; blade elliptic, oblanceolate, or oblong, (0.5–)1.5–6(–10) cm × (3–)10–25(–35) mm (smaller distally), base cuneate, apex acute. Racemes: rachis straight or slightly flexuous. Fruiting pedicels 0.5–2(–4) mm. Flowers: sepals sometimes persistent, (3.5–)4–5 × 0.5–0.7 mm; petals narrowly oblanceolate, (6.5–)8–10(–12) × 1–2 mm; filaments distinct, 2.5–5 mm; anthers narrowly oblong, 0.9–1.1 mm. Fruits divaricate-ascending, straight, (2.5–)3.5–5.5(–7) cm × 1–1.3 mm; valves usually pubescent, rarely glabrous, trichomes coarse and forked, these mixed with smaller, forked, subdendritic, or simple, subsetiform ones; stigma to 1 mm. Seeds 1–1.2 × 0.5–0.6 mm. 2n = 14, 28.
Phenology: Flowering May–Aug.
Habitat: Fields, disturbed areas, roadsides, deserts, sandy flats, vacant lots, sagebrush and greasewood areas, grasslands, railroad tracks, shale outcrops, alkaline flats, juniper woodlands, plains
Elevation: 600-2400 m
Introduced; Ariz., Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wyo., Europe, Asia, n Africa, introduced also in South America (Argentina).