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cirse ou chardon des marais, European Marsh thistle, European swamp or marsh thistle, European swamp thistle, marsh thistle

Parry thistle, Parry's thistle

Habit Biennials or monocarpic perennials, 30–200(–300) cm; clusters of fibrous roots. Biennials, 50–200+ cm; taprooted.
Stems

single, erect, villous to tomentose with jointed trichomes, distally tomentose with fine, unbranched trichomes;

branches 0–few, ascending, (short).

1, erect, puberulent to pilose with jointed trichomes, sometimes also thinly arachnoid;

branches 0–many, ascending, often nodding at tips.

Leaves

blades narrowly elliptic to oblanceolate, 15–30+ × 3–10 cm, margins shallowly to very deeply pinnatifid, narrow lobes separated by broad sinuses, spiny-dentate to lobed, main spines 2–6 mm, abaxial villous to tomentose with jointed trichomes, sometimes also thinly tomentose with fine unbranched trichomes, adaxial faces villous with septate trichomes or glabrate;

basal often present at flowering, petioles spiny-winged, bases tapered;

cauline many, sessile, gradually reduced and becoming widely spaced above, bases long-decurrent with prominently spiny wings;

distal cauline deeply pinnatifid with few-toothed spine-tipped lobes.

blades oblong to lanceolate or oblanceolate, 10–30 × 2–5 cm, margins flat to undulate, spinulose and otherwise entire to coarsely dentate or shallowly to deeply pinnatifid, lobes well separated, spinulose to coarsely few-dentate, main spines slender to stout, 1–15 mm, one or both faces thinly pilose, sometimes thinly arachnoid, green and ± glabrescent at maturity;

basal usually absent at flowering, sessile or winged-petiolate;

principal cauline well distributed, proximal absent at flowering, moderately reduced distally, winged-petiolate or sessile (proximal), sessile and auriculate-clasping to slightly decurrent 0–2 cm;

distal well developed, spreading, lobed or unlobed.

Peduncles

0–1 cm.

0–4 cm.

Involucres

ovoid to campanulate, 1–1.5 × 0.8–1.3 cm, thinly cobwebby tomentose with fine unbranched trichomes.

hemispheric to subspheric, 1.5–2.5 × 1.5–3 cm, glabrous to finely arachnoid and/or pilose, often long pilose-ciliate with arachnoid trichomes connecting adjacent phyllaries.

Corollas

lavender to purple (white), 11–13 mm, tubes 5–7 mm, throats 2–3 mm, lobes 3–4.5 mm;

style tips 1.5–2 mm.

ochroleucous to ± yellow (rarely white or purple), 11–17 mm, tubes 5.5–11 mm, throats 2–4 mm, lobes 3–5 mm;

style tips 2–4 mm.

Phyllaries

in 5–7 series, strongly imbricate, greenish, or with purplish tinge, lanceolate to ovate (outer) or linear-lanceolate (inner), margins thinly arachnoid-ciliate, abaxial faces with narrow glutinous ridge, outer and middle appressed, entire, apices acute, mucronate or spines erect or spreading, weak, 0.3–1 mm;

apices of inner phyllaries purplish, linear-attenuate, scarious, flat.

in 5–8 series, imbricate to subequal, proximally greenish, distally darker, becoming brownish, linear to narrowly lanceolate, outer often nearly as long as inner, abaxial faces with poorly developed glutinous ridge;

outer and mid bases appressed, apices loosely ascending to spreading, bodies entire to spiny-ciliate or terminal appendages expanded, ± scarious, pectinately fringed, spines straight, 2–6 mm;

apices of inner flat or spine-tipped, sometimes expanded and fimbriate.

Heads

few–many in dense clusters at branch tips.

1–many, ± erect, loosely to densely clustered at tip of main stem and branches in subcapitate to racemiform arrays, often also in distal leaf axils, closely subtended by clusters of unlobed to deeply dissected, often very spiny bracts.

Cypselae

tan to stramineous, 2.5–3.5 mm, apical collars 0.1–0.2 mm, shiny;

pappi 9–11 mm.

tan to dark brown, 4–6 mm, apical collars narrow, not differently colored;

pappi 9–15 mm.

2n

= 34.

= 34.

Cirsium palustre

Cirsium parryi

Phenology Flowering summer (Jul–Aug). Flowering summer–fall (Jul–Oct).
Habitat Marshes, wet forests Stream banks, montane meadows, damp soil in montane coniferous forests
Elevation 10–800 m (0–2600 ft) 2100–3700 m (6900–12100 ft)
Distribution
from FNA
MA; MI; NH; NY; WI; BC; NF; NS; ON; QC; SPM; Europe [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; NM
[WildflowerSearch map]
[BONAP county map]
Discussion

Cirsium palustre is a noxious weed, native to Europe, that invasively spreads through wetland communities, forming impenetrable spiny stands as it displaces native species. The range of this pernicious weed in North America is rapidly expanding. It has the potential to spread into boreal forest areas across the continent; in Europe it grows nearly to the Arctic Circle. The rapid spread of C. palustre in Michigan (E. G. Voss 1972–1996, vol. 3) is indicative of its invasiveness. Spontaneous hybrids between C. palustre and C. arvense have been reported from England and other European countries (W. A. Sledge 1975) and can be expected wherever these species grow together in North America.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Cirsium parryi ranges from the Rocky Mountains of central and southern Colorado south to the San Francisco Peaks, Pinaleno Mountains, and White Mountains of Arizona, and the Mogollon and Sacramento ranges of southern New Mexico. Within this broad range several minor variants have been recognized at the species level. The features that supposedly distinguish C. gilense, C. inornatum, and C. pallidum vary widely and inconsistently through the range of the species. In like manner the characters used by Schaack and Goodwin to distinguish subsp. mogollonicum fall well within the variation of the species as a whole and do not seem adequate to separate subsp. mogollonicum from the rest of C. parryi at any taxonomic rank. Cirsium parryi hybridizes with C. grahamii in Arizona and C. canescens in Colorado.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 19, p. 110. FNA vol. 19, p. 149.
Parent taxa Asteraceae > tribe Cardueae > Cirsium Asteraceae > tribe Cardueae > Cirsium
Sibling taxa
C. altissimum, C. andersonii, C. andrewsii, C. arizonicum, C. arvense, C. barnebyi, C. brevifolium, C. brevistylum, C. canescens, C. carolinianum, C. ciliolatum, C. clavatum, C. crassicaule, C. cymosum, C. discolor, C. douglasii, C. drummondii, C. eatonii, C. edule, C. engelmannii, C. flodmanii, C. foliosum, C. fontinale, C. grahamii, C. helenioides, C. hookerianum, C. horridulum, C. hydrophilum, C. inamoenum, C. joannae, C. kamtschaticum, C. lecontei, C. longistylum, C. mohavense, C. muticum, C. neomexicanum, C. nuttallii, C. occidentale, C. ochrocentrum, C. ownbeyi, C. parryi, C. perplexans, C. pitcheri, C. praeteriens, C. pulcherrimum, C. pumilum, C. quercetorum, C. remotifolium, C. repandum, C. rhothophilum, C. rydbergii, C. scariosum, C. texanum, C. tracyi, C. turneri, C. undulatum, C. vinaceum, C. virginianum, C. vulgare, C. wheeleri, C. wrightii
C. altissimum, C. andersonii, C. andrewsii, C. arizonicum, C. arvense, C. barnebyi, C. brevifolium, C. brevistylum, C. canescens, C. carolinianum, C. ciliolatum, C. clavatum, C. crassicaule, C. cymosum, C. discolor, C. douglasii, C. drummondii, C. eatonii, C. edule, C. engelmannii, C. flodmanii, C. foliosum, C. fontinale, C. grahamii, C. helenioides, C. hookerianum, C. horridulum, C. hydrophilum, C. inamoenum, C. joannae, C. kamtschaticum, C. lecontei, C. longistylum, C. mohavense, C. muticum, C. neomexicanum, C. nuttallii, C. occidentale, C. ochrocentrum, C. ownbeyi, C. palustre, C. perplexans, C. pitcheri, C. praeteriens, C. pulcherrimum, C. pumilum, C. quercetorum, C. remotifolium, C. repandum, C. rhothophilum, C. rydbergii, C. scariosum, C. texanum, C. tracyi, C. turneri, C. undulatum, C. vinaceum, C. virginianum, C. vulgare, C. wheeleri, C. wrightii
Synonyms Carduus palustris Cnicus parryi, C. gilense, C. inornatum, C. pallidum, C. parryi subsp. mogollonicum
Name authority (Linnaeus) Scopoli: Fl. Carniol. ed. 2, 2: 128. (1772) (A. Gray) Petrak: Bot. Tidsskr. 31: 68. (1911)
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