Erysimum inconspicuum (S. Watson) MacMillan var. coarctatum (Fernald) Rossbach

Biennials or perennials; (caudex thickened, usually simple, rarely branched). Trichomes of leaves 2- (or 3-) rayed. Stems erect, unbranched or branched basally and/or distally, (0.8-) 1.5-7(-9.4) dm. Basal leaves: blade oblanceolate to linear-oblanceolate, 2-7 cm × 2-7 mm, base attenuate, margins entire or denticulate, apex acute. Cauline leaves sessile; blade margins entire or denticulate. Racemes (densely flowered), elongated or not in fruit. Fruiting pedicels usually ascending, rarely divaricate-ascending, stout, slightly narrower than fruit, (often crowded), 4-7(-10) mm. Flowers: sepals linear-oblong, 5-8 mm, lateral pair saccate basally; petals yellow, narrowly obovate to spatulate, (8-)10-15 × (2-)2.5-4 mm, claw 6-9 mm, apex rounded; median filaments 6-10 mm; anthers narrowly linear, 1.7-2 mm. Fruits suberect to ascending, (subappressed to rachis or not), narrowly linear, straight, not torulose, 2.5-5.8(-6.4) cm × 1.8-2.5 mm, slightly 4-angled, not striped; valves with somewhat prominent midvein, pubescent outside, trichomes 2-4-rayed, glabrous inside; ovules 40-56 per ovary; style stout, 0.5-1.5 mm, moderately to sparsely pubescent; stigma strongly 2-lobed, lobes as long as wide. Seeds ovoid to oblong, 1.5-2 × 1-1.2 mm; not winged. 2n = 54.

Flowering Jul-Aug. Calcareous talus and cliffs, meadows, bluffs, spruce forests, roadsides, crevices, ledges; 200-3000 m; Alta., Nfld. and Labr. (Nfld.), N.W.T., Que., Yukon; Alaska.

Both G. B. Rossbach (1958, 1958b) and R. C. Rollins (1993) treated Erysimum coarctatum as a variety of E. inconspicuum. However, the morphological and cytological (G. A. Mulligan 2002) differences clearly support its maintenance as a distinct species. The vast majority of the collections from Yukon belong to E. coarctatum, and the species is reported herein from Alberta [Banff, Clark s.n., July-August (GH)] for the first time. The records from Alaska are based on Scamman 5062 (GH) from Eklutna Lake and Wiggins 12886 (GH) from Umiat on Colville River.