Description from Flora of China
Herbs biennial or perennial, 20-90 cm tall. Trichomes almost exclusively malpighiaceous, rarely mixed with few 3-forked ones especially on style. Stems erect, simple or branched basally, angled. Basal leaves rosulate; petiole 1-6 cm; leaf blade linear to linear-lanceolate, (1-)2-6(-8) cm × 2-5(-10) mm, flat, base attenuate, margin entire, apex acute. Upper cauline leaves sessile, entire. Racemes corymbose, densely flowered, ebracteate, elongated considerably in fruit. Fruiting pedicels divaricate or suberect, (3-)4-8(-10) mm, stout, narrower than fruit, straight or curved upward. Sepals oblong-linear, 6-8(-9) × 1-1.5 mm, lateral pair slightly saccate. Petals yellow, spatulate, 1-1.5(-1.7) cm × (1.5-)2.5-3.5 mm, apex rounded; claw distinct, subequaling or longer than sepals. Filaments yellow, 6-9 mm; anthers linear, 2-3 mm. Ovules 70-110 per ovary. Fruit linear, strongly 4-angled, (3.5-)5-8(-10) cm × 1-1.5 mm, not torulose, erect and subappressed to rachis, or ascending to divaricate, straight or slightly curved; valves outside with four bands of trichomes separated by glabrous replum and valve midveins, inside glabrous; style slender, 1-3 mm, cylindric, narrower than fruit; stigma capitate, entire. Seeds oblong, 1-1.3 × 0.4-0.6 mm. Fl. May-Aug, fr. Jul-Sep.
Erysimum canescens was recognized in FRPS as a synonym E. diffusum Ehrhart. The latter species is restricted to C and S Europe.
Mountain slopes; 700-3800 m. Xinjiang [Kazakhstan, Mongolia, Russia, Tajikistan, Uzbekistan].