Description from Flora of China
Carduus armenus Boissier; C. coloratus Tamamschjan; C. leiophyllus Petrovič; C. nutans subsp. leiophyllus (Petrovič) Stojanov & Stefanov; C. schischkinii Tamamschjan; C. songoricus Tamamschjan; C. thoermeri Weinmann.
Herbs 30-100 cm tall, biennial or perennial. Stems grayish white, usually branched, sparsely cobwebby and hirsute below, densely cobwebby-felted above; wings continuous, unequally toothed; teeth triangular, margin and apex with spines. Leaves green, concolorous, hirsute along veins or sparsely cobwebby. Lower and middle cauline leaves sessile, ovate to lanceolate, (5-)10-40 × (1.5-)3-10 cm, pinnatifid or pinnatipartite; segments 5-7 pairs, obliquely triangular to triangular-ovate, margin spinulose, apex with a 4-6 mm spine. Upper cauline leaves similar but gradually smaller upward, pinnately lobed or entire. Capitula 4-6, solitary at end of stem and branches, ± nodding. Involucre ± broadly campanulate, 4-7 cm in diam. Phyllaries slightly constricted at or beyond middle then expanded into a lanceolate, spiny-tipped, and patent to recurved distal portion; outer phyllaries 14-15 × 4-5 mm; middle and inner phyllaries 1.5-2 × ca. 0.5 cm; innermost phyllaries broadly linear to linear-lanceolate, 2-2.2 × 0.2-0.3 cm, not constricted. Corolla purplish red, ca. 2.5 cm, tube ca. 1.3 cm. Achene grayish yellow with pale brown striae, ca. 3.5 mm. Pappus bristles white, unequal, to 2 cm. Fl. and fr. Jun-Sep. 2n = 16, 40.
Carduus nutans is a variable species. At least fifteen subspecies have been recognized in the western, European part of its range. Carduus nutans subsp. nutans does not extend to Asia. The Chinese plants probably belong to C. nutans subsp. leiophyllus, as the synonymy indicates, but more research is needed.
By croplands, grasslands, valleys; 500-2300 m. N Xinjiang [Kazakhstan, Mongolia, Russia; N Africa, SW Asia, Europe].