Mt. Hamilton thistle

Cirsium campylon H. Sharsmith, Madroño 5: 85, fig. 1. 1939

Basal leaves: longer spines 4–15 mm, distal faces equally glandular and tomentose. Cauline leaves: longer spines 10–18 mm. Distalmost stem bracts typically separated from heads. Phyllaries 65–85, 25–35 of them reflexed; apical spines 3–6 mm; marginal spines usually absent. Cypselae 3.4–4.1 mm. 2n = 34.

Flowering spring-summer (Apr–Aug). Serpentine seeps in areas of chaparral, valley grasslands, foothill woodlands; of conservation concern; 300–800 m; Calif.

Variety campylon is endemic to the Mt. Hamilton Range in Alameda, Santa Clara, and Stanislaus counties.