Description from Flora of China
Microsisymbrium yechengicum Z. X. An, Bull. Bot. Res., Harbin 1(1-2): 99. 1981.
Herbs annual or perennial, 15-50 cm tall, glabrescent or sparsely pubescent with flattened, crisped, simple trichomes to 0.7 mm. Stems erect or subdecumbent, simple or many branched at base. Basal leaves withered by fruiting, not rosulate; petiole 0.5-3 cm, not flattened at base; leaf blade narrowly oblong or linear-lanceolate, 2-4 cm × 1-5 mm, base cuneate, margin coarsely dentate or pinnatifid and lobes to 5 × 1 mm, rarely subentire, apex acuminate. Middle cauline leaves subsessile to petiolate, similar to basal leaves but progressively reduced in size upward, 3-7 cm × 2-6 mm, margin entire or dentate, apex acuminate. Racemes ebracteate, elongated considerably in fruit. Fruiting pedicels divaricate or ascending, recurved or straight, slender, 0.7-1.8(-2.5) cm, glabrescent or sparsely with crisped, simple trichomes. Sepals oblong, 3-4 × 1.5-2 mm, scarious at margin, glabrous. Petals white or pink, obovate, 6-10 × 3-5 mm, apex obtuse; claw 1-2 mm. Filaments white, 2.5-3.5 mm; anthers narrowly oblong, 0.9-1.1 mm, apex obtuse. Fruit (1.5-)2.5-4 cm × 1-1.2 mm, widely spreading; valves glabrescent, rarely sparsely with crisped simple trichomes to 0.5 mm; style 0.4-0.6(-0.9) mm; stigma entire. Seeds yellowish brown, oblong, 1.2-1.7 × 0.8-1 mm, slightly compressed, distal margin with a minute wing. Fl. Jun-Jul, fr. Jul-Aug.
The single paratype cited in the protologue of Microsisymbrium yechengicum is a specimen of Chorispora sibirica.
* Grasslands, mountain slopes, steep rocky river banks; 2500-3000 m. Xinjiang.