Erysimum flavum (Georgi) Bobrov

A highly variable species that can be divided into two infraspecific taxa separable only by quantitative characters. These are recognized here at subspecific rank, and it is likely that their limits become blurred in parts of Siberia and adjacent Mongolia and Xinjiang.

Herbs perennial, 10-60(-100) cm tall; caudex with petiolar remains of previous years. Trichomes exclusively malpighiaceous. Stems erect, simple or several from caudex. Basal leaves rosulate; petiole (0.3-)0.8-2(-4) cm, often grooved adaxially; leaf blade filiform to narrowly linear, rarely linear-oblanceolate, (0.7-)1-6(-9) cm × (0.5-)1-4(-8) mm, folded, base attenuate, margin entire or rarely denticulate, apex acute. Upper cauline leaves sessile, linear to filiform, entire or rarely denticulate. Racemes corymbose, densely flowered, ebracteate, elongated considerably in fruit. Fruiting pedicels divaricate or ascending, 4-15 mm, stout, narrower than fruit, straight. Sepals lanceolate-linear, 5-14 × 1.5-2 mm, lateral pair strongly saccate. Petals yellow, obovate, 0.9-2.6 cm × 3-8 mm, apex rounded; claw distinct, subequaling or longer than sepals. Filaments yellow, 0.5-1.5 cm; anthers linear, 2-4 mm. Ovules 60-130 per ovary. Fruit linear, slightly 4-angled or flattened, (3.5-)5-8(-12) cm × 1-2 mm, slightly torulose, erect-ascending, straight or slightly curved; valves with a distinct midvein, outside with malpighiaceous trichomes, inside glabrous; style slender, (0.5-)1-3(-4) mm, cylindric, narrower than fruit; stigma capitate, 2-lobed. Seeds oblong, 1.5-2.5 × 0.8-1.2 mm. Fl. May-Jun, fr. Jul-Sep.

Heilongjiang, Nei Mongol, Xinjiang, Xizang [Kashmir, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia (Siberia), Tajikistan].

Forest clearings, mountain slopes, dry meadows, steppes, alpine or subalpine areas, tundra; 900-4600 m.