Sisymbrium lasiocarpum J. D. Hooker & Thomson, J. Proc. Linn. Soc., Bot. 5: 162. 1861, not (F. Mueller) F. Mueller (1869); Arabidopsis lasiocarpa (J. D. Hooker & Thomson) O. E. Schulz; A. lasiocarpa var. micrantha W. T. Wang; A. monachorum (W. W. Smith) O. E. Schulz; Guillenia duthiei (O. E. Schulz) Bennet; Hesperis lasiocarpa (J. D. Hooker & Thomson) Kuntze; Microsisymbrium duthiei O. E. Schulz; S. bhutanicum N. P. Balakrishnan, nom. illeg. (included S. lasiocarpum); S. monachorum W. W. Smith.
Herbs annual or biennial, (10-)25-70(-120) cm tall. Stems erect, simple or branched at base, densely hirsute with horizontal simple trichomes to 1.3 mm, these mixed throughout with much smaller, short-stalked, stellate trichomes. Basal leaves not rosulate, petiolate, often caducous by fruiting; petiole (0.3-)1-3 cm; leaf blade spatulate, (0.3-)1-5(-7) cm × (2-)6-11(-20) mm, stellate pubescent and often mixed with simple or forked trichomes, margin dentate or rarely lyrately lobed, apex obtuse. Middle cauline leaves obovate, oblong, or elliptic, sessile and broad at base, (0.6-)1-2(-2.5) cm × (3-)6-11 mm, stellate pubescent, dentate, repand, or entire, reduced in size upward. Racemes bracteate throughout or only lower flowers bracteate; bracts similar to uppermost cauline leaves. Fruiting pedicels slender, stellate pubescent all around, suberect or rarely divaricate, (0.5-)1-4(-6) mm. Sepals oblong, 1.5-2(-2.5) × 0.8-1 mm, densely pubescent, sometimes narrowly membranous. Petals white or pink, spatulate or narrowly oblanceolate, 2-3(-4) × 0.6-0.9 mm, attenuate to base; claw to 1 mm. Filaments 1.5-2.5 mm; anthers oblong-ovate, 0.3-0.4 mm. Ovules 70-160 per ovary. Fruit linear, terete, straight, appressed to rachis or rarely divaricate, (0.6-)1.5-3(-4.2) cm × 0.7-1(-1.3) mm; valves densely stellate pubescent, with an inconspicuous midvein; style 0.3-0.6(-1) mm. Seeds light brown, oblong or subovoid, 0.5-0.6 × 0.3-0.4 mm. Fl. Apr-Aug, fr. May-Sep.
Fields, forest margins, grassy slopes, river banks, limestone scree and slopes, roadsides; 2400-4500 m. Sichuan, Xizang, Yunnan [Bhutan, India (Uttar Pradesh), Nepal].
