Sinapis erucoides Linnaeus, Cent. Pl. II, 24. 1756

Annuals or biennials, not scented. Stems erect, 1-4(-8) dm, densely pubescent throughout, (trichomes retrorse, appressed). Basal leaves: blades elliptic to obovate, 2.5-8 cm × 10-40 mm, margins sinuate to pinnatifid or lyrate, (2-5 lobes each side), (surfaces pubescent throughout, trichomes antrorse). Cauline leaves (distal) sessile; blade (base cuneate to broad, truncate), margins similar to basal, (distally reduced, subtending proximal flowers). Fruiting pedicels 3-10(-22) mm. Flowers: sepals 4-5.5 mm, pubescent, trichomes ± flexuous; petals white (turning purple when dried), 7-10 × 4-5 mm; filaments 4-6.5 mm; anthers 1.5-2 mm; gynophore obsolete or to 0.5 mm. Fruits erect-patent, 2-3.5(-4) cm × 1.5-2(-2.5) mm; terminal segment beaklike, 2-5 mm, 1- or 2-seeded. Seeds 1-1.2 × 0.5-0.8 mm. 2n = 14.

Flowering summer. Ballast and waste places; introduced; Que.; Calif., Mass., N.J.; Eurasia; Africa; introduced also in South America (Argentina).

Diplotaxis erucoides was introduced from Europe as a ballast plant in the last century and may have failed to persist in some of the recorded provinces and states.