Description from Flora of China
Lepidium calycinum Stephan in Willdenow, Sp. Pl. 3: 433. 1800; Chrysanthemopsis koelzii K. H. Rechinger; Hutchinsia calycina (Stephan) Desvaux; H. calycina (Stephan) Desvaux var. pectinata (Bunge) Regel & Herder; H. pectinata Bunge; Smelowskia calycina var. pectinata (Bunge) B. Fedtschenko; S. koelzii (K. H. Rechinger) K. H. Rechinger; S. pectinata (Bunge) Velichkin; S. tianschanica Velichkin.
Herbs (3.5-)7-30(-40) cm tall, canescent basally or throughout. Stems often simple above, densely pubescent with simple trichomes to 2 mm and/or much smaller dendritic ones, sometimes glabrescent. Basal leaves with petioles (0.5-)1-5(-7) cm, ciliate with simple trichomes or not ciliate; leaf blade 1- or 2-pinnatiscet, oblong, lanceolate, or ovate in outline, 1.5-8 × 0.4-1.5 cm; ultimate segments linear, oblong, or ovate, to 15 × 3 mm, apex obtuse or subacute. Middle and upper cauline leaves sessile or subsessile, smaller and less divided than basal ones, sometimes pectinate. Inflorescence often simple. Fruiting pedicels suberect or ascending, rarely divaricate, slender, 5-10(-14) mm, pubescent with dendritic and/or simple straight trichomes. Sepals ovate, 2.5-4 × 1.5-2 mm, caducous or persistent. Petals white or pale yellow, suborbicular or obovate, (3.5-)5-7 × 2-4 mm, rounded at apex, narrowed to claw 1-2.5 mm. Filaments 1.5-3.5 mm; anthers oblong, 0.5-0.8 mm. Ovules 4-10(-12) per ovary. Fruit ellipsoid or oblong, rarely ovoid or linear-ellipsoid, (3-)5-9(-10) × 1.5-2.5 mm, cuneate at least at apex; valves with a prominent midvein; gynophore obsolete or to 0.5 mm; septum perforated or complete, with a midvein distally; style 0.5-1(-1.5) mm. Seeds brown, oblong or subovate, 1.1-1.8 × 0.8-1.1 mm. Fl. Jun-Aug, fr. Jul-Sep.
Smelowskia calycina is highly variable and has been divided in both Asian and North American accounts into several, poorly defined species or varieties. In the absence of authoritative studies on the species throughout its range, it is better not to recognize any infraspecific taxa. The Chinese plants are a good match for the type collection of the species. Synonyms pertaining only to C Asia are listed above.
Rocky slopes, gravelly hills, rocky crevices, alpine meadows; 2500-4900 m. Xinjiang [Afghanistan, India, Kashmir, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia (Far East, Siberia), Tajikistan; North America].