Cirsium ochrocentrum
Mem. Amer. Acad. Arts, n. s. 4: 110. 1849.
Perennials, 30–90 cm; crown sprouts or runner roots producing adventitious buds. Stems 1–20+, erect or ascending, densely gray-tomentose with non-septate trichomes; branches 0 or few, usually in distal 1/2, ascending. Leaves: blades oblong to narrowly elliptic, 10–30 × 2–8 cm, strongly undulate, margins coarsely dentate or shallowly to deeply pinnatifid with 8–15 pairs of lobes 0.5–2 cm, often revolute, lobes ± triangular, closely spaced, spreading, spinose-dentate and cleft into 2–5 spine-tipped divisions, main spines 5–20 mm, yellowish, abaxial faces densely white-tomentose, adaxial thinly gray-tomentose; basal usually present at flowering, winged-petiolate; principal cauline sessile, progressively reduced distally, bases ± auriculate to long-decurrent as spiny wings; distal cauline usually much reduced, less lobed. Heads 1–few, in leafy, ± corymbiform arrays. Peduncles 0–4 cm. Involucres ovoid to hemispheric or broadly campanulate, 2.5–4.5 × 2.5–4.5 cm in first-formed heads, often smaller in later ones, loosely arachnoid on phyllary margins or glabrate. Phyllaries in 5–10 series, imbricate, ovate (outer) to linear-lanceolate (inner), margins entire, abaxial faces with narrow glutinous ridge; outer and middle appressed, spines spreading, 3–12 mm; apices of inner often flexuous, expanded and flat, scabrid-margined, sometimes erose, spineless. Corollas white or pale lavender to purple, pink, or red, 25–45 mm, tubes 8–25 mm, throats 6–17 mm, lobes 6–15 mm; style tips 2–8 mm. Cypselae light brown, sometimes with lighter or darker streaks, 6–9 mm, apical collars colored like the body, narrow; pappi (white or tawny), 20–40 mm, usually noticeably shorter than corolla. 2n = 30, 31, 32, 34.
Distribution
Ariz., Calif., Colo., Kans., N.Mex., Nebr., Okla., S.Dak., Tex., Utah, Wyo., n Mexico.
Discussion
Varieties 2 (2 in the flora).
Selected References
None.
Key
| 1 | Stems densely leafy, nodes crowded; leaves often long- decurrent; corollas white or pale lavender to purple | Cirsium ochrocentrum var. ochrocentrum |
| 1 | Stems leafy, nodes usually well separated; distal cauline leaves clasping, or if decurrent spiny wing usually less than 1 cm; corollas red, pink, or reddish purple (rarely white) | Cirsium ochrocentrum var. martinii |