Hall’s thistle

Cirsium hallii (A. Gray) M. E. Jones

Heads usually crowded at stem tips. Peduncles 0–1(–4) cm. Involucres 1.5–2.5 × 1.5–3 cm, thinly to densely arachnoid. Phyllary apices ascending or ± spreading, plane to acicular, spines 1–5 mm. Corollas 14–21 mm, tubes 5–11 mm, throats 4–8 mm, lobes 4–6 mm; style tips 3–4 mm. Cypselae light to dark brown, 3.5–4.5 mm; pappi 9–13 mm.

Flowering summer (Jun–Aug). Sea bluffs, roadsides, damp soil at edge of woods, openings in conifer or conifer-hardwood forests; 0–900 m; Oreg., Wash.

Variety edule is known from the coast and coast ranges of Oregon and Washington. Some coastal populations of var. edule approach montane forms of var. macounii in stature, head size, and involucre pubescence. Some of the variation in var. edule may be a result of past introgression with Cirsium remotifolium. Populations of var. edule from within the ranges of C. remotifolium vars. odontolepis, remotifolium, and rivulare often show features of those taxa.