Cirsium pumilum |
Cirsium helenioides |
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pasture thistle |
melancholy thistle |
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Habit | Biennials or monocarpic perennials, 25–100 cm; sometimes perennating by root sprouts. | Perennials, 40–120 cm; runner roots. | ||||
Stems | erect, villous with septate trichomes and sometimes thinly arachnoid tomentose; branches 0–few, distal, ascending. |
single, erect, ± arachnoid-tomentose; branches 0 or few, ascending. |
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Leaves | blades oblong-elliptic, 5–30+ × 2–10 cm, ± undulate, shallowly to deeply pinnatifid, lobes ovate to broadly triangular, usually separated by broad sinuses, spinose-dentate or lobed, main spines 1.5–7 mm, slender to stout, abaxial faces villous with septate trichomes, at least along veins, sometimes thinly arachnoid, adaxial faces villous with septate trichomes and thinly arachnoid tomentose or subglabrous; basal often present at flowering, bases tapered; principal cauline sessile, moderately reduced distally, bases often auriculate-clasping; distal reduced, similar to proximal. |
oblong to broadly lanceolate, 20–40 × 4–8 cm, finely spinulose-dentate or proximal cauline pinnatifid, lobes undivided, finely spinulose-dentate, main spines 1–2 mm, abaxial faces white-tomentose (with non-septate trichomes), adaxial glabrous; basal present at flowering, petiolate, bases tapered; cauline sessile, reduced distally, bases clasping, not decurrent; distal (few, well separated), oblong or linear, the uppermost reduced to linear bracts. |
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Peduncles | 0–15+ cm (above distal leaves), leafy-bracted. |
2–10(–30) cm (elevated above distal leaves). |
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Involucres | broadly cylindric to ovoid, 3.5–5 cm, 2.5–3 cm diam. (appearing much wider and hemispheric to campanulate in pressed specimens), loosely arachnoid on phyllary margins or glabrate. |
broadly ovoid, 2–3 × 2–3.5 cm, glabrous or loosely arachnoid. |
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Corollas | pink to purple (white), 40–60 mm, tubes 20–35 mm, throats 11–15 mm, lobes 7–10 mm; style tips 3–7 mm. |
red-purple, 25–30 mm, tubes 10–23 mm, throats 8–14 mm (noticeably wider than tubes), lobes 7–10 mm; style tips 4–5 mm. |
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Phyllaries | in 8–10 series, imbricate, ovate or lanceolate (outer) to lance-linear (inner), abaxial faces with ± prominent glutinous ridge, outer and middle appressed, apices ascending to spreading, spines 1.5–6 mm; apices of middle and inner narrowed and scabrid-denticulate, innermost spineless, tapered and entire or with expanded, erose-denticulate, flexuous tips. |
in 8–10 series, imbricate, green, ovate or lanceolate (outer) to linear-lanceolate (inner), abaxial faces with a prominent elongate glutinous ridge, outer and middle tightly appressed, margins entire, apices with ascending, weak spines 0–1 mm; apices of inner phyllaries attenuate, flat. |
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Heads | 1–few, borne singly at tips of main stem and branches, often closely subtended by 1–several bracts. |
borne singly or less commonly 2–5 in terminal clusters. |
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Cypselae | stramineous to brown, 3.5–5 mm, apical collars yellow or colored like body; pappi 35–45 mm. |
light brown, 3–5 mm, bodies and apical collars concolorous; pappi 20–30 mm. |
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2n | = 30. |
= 34. |
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Cirsium pumilum |
Cirsium helenioides |
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Phenology | Flowering summer (Jul–Aug). | |||||
Habitat | Fjordlands | |||||
Elevation | 0–50 m (0–200 ft) | |||||
Distribution |
CT; DE; IA; IL; IN; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; RI; SC; VA; VT; WI; WV; ON; United States
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Greenland; Iceland; Europe; Asia |
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Discussion | Varieties 2 (2 in the flora). Flowers of Cirsium pumilum are reportedly sweetly scented. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cirsium helenioides is one of only two species of the genus that have native populations in the Old World and the flora area. Neither reaches the North American mainland. The conservation status of Cirsium helenioides is not known; it is known in the flora area only from a single fjord and possibly should be considered of conservation concern. of conservation concern (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 19, p. 116. | FNA vol. 19, p. 110. | ||||
Parent taxa | Asteraceae > tribe Cardueae > Cirsium | Asteraceae > tribe Cardueae > Cirsium | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Carduus pumilus | Carduus helenioides, C. heterophyllum | ||||
Name authority | (Nuttall) Sprengel: Syst. Veg. 3: 375. (1826) | (Linnaeus) Hill: Hort. Kew., 64. (1768) | ||||
Web links |