Erysimum asperum (Nuttall) de Candolle var. inconspicuum S. Watson, Botany (Fortieth Parallel), 24. 1871; Cheiranthus inconspicuus (S. Watson) Greene; C. syrticola (E. Sheldon) Greene; Cheirinia inconspicua (S. Watson) Rydberg; C. parviflora Farwell; C. syrticola (E. Sheldon) Rydberg; E. asperum var. parviflorum M. E. Jones; E. inconspicuum var. syrticola (E. Sheldon) Farwell; E. syrticola E. Sheldon

Biennials or perennials; (short-lived, caudex thickened, usually simple, rarely branched). Trichomes of leaves 2- or 3-rayed. Stems erect, unbranched or branched distally, 1.5-7 dm. Basal leaves: blade linear to linear-oblanceolate, 1.5-6(-8) cm × 2-8 mm, base attenuate, margins entire or dentate, apex acute. Cauline leaves (distal) sessile; blade margins entire or denticulate. Racemes elongated or not in fruit. Fruiting pedicels divaricate-ascending to ascending, stout, slightly narrower than fruit, 4-9(-15) mm. Flowers: sepals oblong to linear-oblong, 4-6 mm, lateral pair slightly saccate basally; petals yellow, oblanceolate, 6-9 (-11) × 1-2 mm, claw 5-7 mm, apex rounded; median filaments 5-7 mm; anthers narrowly oblong to linear, 1-2 mm. Fruits ascending to divaricate-ascending, (not appressed to rachis), narrowly linear, straight, not torulose, 3-5.8(-7) cm × 1-1.5(-1.8) mm, slightly 4-angled or terete, not striped; valves with somewhat prominent midvein, pubescent outside, trichomes 2-4-rayed, glabrous inside; ovules 36-66 per ovary; style cylindrical, stout, 0.7-3 mm, moderately to sparsely pubescent; stigma strongly 2-lobed, lobes as long as wide. Seeds ovoid, 1.2-1.7 × 0.8-1 mm; not winged or wing apiculate. 2n = 81.

Flowering Apr-Aug. Calcareous talus and cliffs, roadsides, railroad embankments, abandoned fields, hillsides, alkaline ground, bluffs, crevices and ledges, gravel, prairies, rocky pastures, among brush, waste sites; 100-2700 m; Alta., B.C., Man., N.S., Ont., Que., Sask., Yukon; Alaska, Ark., Colo., Idaho, Ill., Ind., Kans., Maine, Mich., Minn., Mo., Mont., Nev., N.H., N.Y., N.Dak., Ohio, Okla., Oreg., S.Dak., Utah, Wis., Wyo.

Erysimum inconspicuum is known in Yukon from Raup & Correll 11255 (A), which was collected 7 miles east of Little Atlin Lake, and Malte s.n. (GH), which was collected from Dawson on 10 August 1916. Most of the other collections from Yukon identified as E. inconspicuum belong to E. coarctatum. The record from Quebec is based on Cayouette J80-8 (GH), from Cté de Charlevoix, and Victorin, Germain, & Meilleur 43128 (GH), from Du Lac-Saint-Jean.