Annuals. Trichomes of leaves 2-rayed, mixed with fewer 3-rayed ones. Stems erect, unbranched or branched basally, (0.4-)1.5-4.5(-7) dm. Basal leaves (often withered by fruiting), similar to cauline. Cauline leaves: (proximal and median) petiolate and (distal) sessile, (petiole (0.3-) 0.5-2(-3) cm); blade [linear, narrowly oblanceolate, elliptic, or oblong, (1-)2-8(-11) cm × (2-)5-12(-17) mm, base attenuate], margins sinuate or coarsely dentate to denticulate or repand, (distal) entire or denticulate, (apex acute). Racemes considerably elongated in fruit. Fruiting pedicels divaricate, stout, as wide as fruit, 2-4(-6) mm. Flowers: sepals linear-oblong, 4-6 mm, lateral pair not saccate basally; petals yellow, narrowly oblanceolate to spatulate, 6-8 × 1.5-2 mm, claw 3-6 mm, apex rounded; median filaments 4-6 mm; anthers narrowly oblong, 0.8-1.3 mm. Fruits widely spreading to divaricate-ascending, narrowly linear, straight or curved upward, somewhat torulose, (2-)3-8(-10) cm × 1.5-2 mm, 4-angled, not striped; valves with prominent midvein, pubescent outside, trichomes 2-rayed and, fewer, 3-rayed, often glabrous, sometimes pubescent inside; ovules (40-)50-80(-90) per ovary; style cylindrical or subclavate, stout, 1-4 mm, sparsely pubescent; stigma slightly 2-lobed, lobes as long as wide. Seeds oblong, 1.1-1.5 × 0.6-0.7 mm; not winged or, rarely, winged distally. 2n = 16.
Annual herb with a stout taproot 20 - 40 cm tall Stem: single or multiple from base, upright, often much-branched, pale green, keeled with longitudinal ridges, hairy (with forked, appressed hairs). Flowers: in a long, branched cluster (raceme), which is borne terminally on the stem. The main stem of the raceme often zigzag. Stalks spreading, 2 - 8 mm long, very thick. Sepals four, upright, light green, broad, linear, densely hairy (hairs star-shaped). Petals four, yellow to yellow and white, 6 - 10 mm long, bases narrowed. Stamens six. Fruit: a long, narrow pod (silique), widely spreading to upright, 5 - 12 cm long, four-angled, beaked, with forked, appressed hairs. Beak to 4 mm long. Stalks to 5 mm long, thick, and nearly at right angles to the stem. Basal leaves: (early in the season) in a rosette, pale green, to 10 cm long, to 1 cm wide, tips often curled or hooked. Stem leaves: alternate, stalkless to short-stalked, pale green, reducing in size upward, linear to narrowly oblong, bases tapering, coarsely toothed to slightly toothed, with forked, appressed hairs.
Similar species: The similar Erysimum cheiranthoides differs by having petals that do not typically exceed 5 mm long, sepals that do not typically exceed 3.5 mm long, and fruit that does not typically exceed 3 cm long. Erysimum inconspicuum and E. hieraciifolium, which are grayish green perennials, differ in having fruit that does not exceed 5 cm long.
Flowering: late April to late June
Habitat and ecology: Introduced from Europe. Occasional along roads, railroads, and in nursery plots. Look for it in disturbed, often sandy ground.
Occurence in the Chicago region: non-native
Etymology: Erysimum comes from the Greek word eryomai, meaning "to help or save," which refers to the medicinal qualities of some species. Repandum means "with wavy margins."
Author: The Morton Arboretum
Duration: Annual Nativity: Non-Native Lifeform: Forb/Herb General: Introduced annual herb; stems usually much branched, 10-50 cm tall; pubescent throughout with short, appressed hairs. Leaves: Basal and cauline, mostly lanceolate, wavy margined and finely toothed, 1-11 cm long, 1-8 mm wide; pubescent with short, appressed hairs. Flowers: Sepals 3-6 mm long, yellowish or greenish; petals 5-8 mm long, yellow. Fruits: Pedicels 2-5 mm long, nearly or as wide as the fruits; siliques 3-8 cm long, 1-2 mm wide, glabrous or nearly so, generally spreading to ascending. Ecology: Disturbed areas from 4,000-7,000 ft (1219-2134 m); flowers March-July. Notes: Annual, with small flowers and generally a highly branching habit. Ethnobotany: Unknown Etymology: Erysimum is Greek meaning to help, given for its medicinal uses, name given by Theophratus, while repandum is ancient word referring to wavy margin. Synonyms: Cheirinia repanda Editor: SBuckley, 2010
Annual, 2-4 dm, often much- branched; lvs linear to narrowly lanceolate or oblanceolate, the smaller often entire, the larger commonly conspicuously sinuate-dentate to pinnatifid; sep densely stellate, 4.5-5.5 mm; pet pale yellow, 6-10 mm; anthers 1 mm; mature racemes elongate, the rachis often zigzag, the pedicels very thick, divergent, 2-8 mm; frs widely spreading, 5-12 cm; 2n=14, 16. Native of Europe, found as an occasional weed in waste places in our range and westward. (Cheirinia r.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.