Cirsium pulcherrimum |
Cirsium vulgare |
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bull thistle, common thistle |
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Habit | Plants biennial, 3–20 dm; taprooted. | |
Stems | usually single, spreading-villous, sometimes arachnoid. |
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Leaves | oblong-lanceolate to obovate, 15–40 × 6–15 cm; margins 1–2-pinnate; lobes lanceolate to triangular; spines 2–10(15) mm; surfaces abaxially tomentose; ± villous, adaxially glabrate to sparsely tomentose, with appressed bristle-like spines; basal absent or present at flowering, sessile, decurrent, or petiolate. |
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Involucres | hemispheric to campanulate, 2–4 × 2–4 cm, thinly tomentose. |
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Florets | corollas 25–35 mm, purple, rarely white; tubes 18–25 mm; throats 3–6 mm; lobes 5–9 mm; style tips 3.5–6 mm. |
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Phyllaries | without glutinous ridges; spines 1–5 mm. |
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Fruits | 3–5 mm, light brown with darker streaks; pappi 20–30 mm. |
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Heads | few to many. |
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Cirsium pulcherrimum |
Cirsium vulgare |
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Distribution | ||
Discussion | Disturbed areas, pastures. Flowering Jun–Sep. 0–2000 m. All ecoregions. CA, ID, NV, WA; throughout North America; worldwide. Exotic. Cirsium vulgare is our only species with bristle-like spines on the upper leaf surface. This species is considered a noxious weed and is unpalatable to most livestock. |
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Source | Flora of Oregon, volume 2, page 230 Bridget Chipman |
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Sibling taxa | ||
Web links |
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