Hesperis africana Linnaeus, Sp. Pl. 2: 663. 1753; Malcolmia africana (Linnaeus) W. T. Aiton

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.

Flowering May-Aug. Fields, disturbed areas, roadsides, deserts, sandy flats, vacant lots, sagebrush and greasewood areas, grasslands, railroad tracks, shale outcrops, alkaline flats, juniper woodlands, plains; 600-2400 m; introduced; Ariz., Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wyo.; Europe; Asia; n Africa; introduced also in South America (Argentina).