Chorro Creek bog thistle

Basal leaves: longer spines 5–9 mm; distal faces more densely glandular than tomentose. Cauline leaves: longer spines 4–7 mm. Distalmost stem bracts tightly subtending heads or separated from them. Phyllaries 70–120, 28–38 of them reflexed; apical spines 2–3 mm; marginal spines usually absent. Cypselae 3.8–4 mm. 2n = 34.

Flowering winter–summer (Jan–Sep). Serpentine seeps, coastal live oak woodlands, grasslands, riparian areas; of conservation concern; 40–300 m; Calif.

Variety obispoense is known only from the southern Santa Lucia and San Luis ranges of San Luis Obispo County.