Erysimum siliculosum is a biennial or perennial herb from Xinjiang, Kazakhstan, Russia, and Turkmenistan, reaching 30-90 cm in height.

Basal leaves rosulate, often persisting, petiolate; leaf blade filiform to linear, rarely linear-oblanceolate, 1.5–8 cm × 1-2(-5) mm, longitudinally folded, base narrowly attenuate, margin entire, apex acute.

Sepals are oblong-linear, (6-)7-9(-10) × 1–2 mm, united, persistent well after fruit maturity, strongly saccate.

Petals are bright yellow, obovate or broadly spatulate, (1.1-)1.4-1.8(-2) cm × 5–8 mm, apex rounded; claw distinct, subequaling sepals.

Fruit are oblong to oblong-linear, strongly 4-angled, slightly angustiseptate, (5-)7-10(-14) × 2–3 mm, smooth, erect and often appressed to rachis, straight; valves with a prominent midvein and slightly winged keel, outside with transversely oriented malpighiaceous trichomes, inside glabrous; style slender, (4-)5-10(-12) mm, cylindric; stigma strongly 2-lobed, with lobes often divergent.