Stems erect or ascending, stout, 40-150 cm. Leaf faces glabrous or nearly so. Heads usually short-pedunculate in erect, racemiform arrays or sometimes long-pedunculate in openly corymbiform arrays. Involucres 3-5 cm, glabrous or thinly arachnoid tomentose, individual phyllaries evident. Phyllaries green or purplish-tinged; outer pectinately spiny 1/2 their length with many lateral spines; apical spines stout. Corollas purple, 24-33 mm, tubes 3.5-7 mm, throats 11-14 mm, lobes 8-12.5 mm. Pappi 16-18 mm. 2n = 34 (as C. clokeyi).
Flowering summer (Jul-Sep). Gravelly slopes, ravines, montane coniferous forests, subalpine forests, alpine scree; of conservation concern; 2300-3500 m; Nev.
Variety clokeyi is endemic to the Spring Range of Clark County. Its range overlaps that of Cirsium arizonicum var. tenuisectum but no hybrids between the two are known.