Flora of North America species comparison

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Cirsium palustre

Cirsium engelmannii

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

blackland thistle, Engelmann's thistle
Habit Biennials or monocarpic perennials, 30–200(–300) cm; clusters of fibrous roots. Biennials or monocarpic perennials, 40–200 cm; taproots and clusters of coarse fibrous roots that often have tuberlike thickenings.
Stems

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

branches 0–few, ascending, (short).

single, erect, often branched above middle, thinly arachnoid-tomentose, ± glabrate;

branches few, ascending.
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 elliptic or ovate, 5–20 × 1–10 cm, usually deeply pinnatifid, lobes narrowly to broadly triangular, sinuses broad, rounded (basal and distal cauline sometimes less divided, lobes linear-lanceolate), margins revolute, spreading, entire or spinulose to remotely few-toothed or sharply lobed, main spines slender, 1–5 mm, abaxial faces white-tomentose, adaxial green, villous with septate trichomes or glabrate;

basal usually absent at flowering, winged-petiolate, bases tapered;

principal cauline well distributed, gradually reduced, bases narrowed, sometimes weakly clasping;

distal reduced, widely separated, distalmost bractlike.
Peduncles

0–1 cm.

2–20+ cm, essentially naked with much reduced bracts.
Involucres

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

ovoid to broadly cylindric or campanulate, 2.5–3.5 × 2–3 cm, thinly arachnoid.
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.

pink to purple (white), 32–38 mm, tubes 15–20 mm, throats 6–9 mm, lobes 8–11 mm;

style tips 5–6 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 10–12 series, strongly imbricate, greenish with subapical darker central zone, ovate (outer) to lanceolate (inner), abaxial faces with narrow glutinous ridge;

outer and middle entire, bodies appressed, spines abruptly spreading to deflexed, slender, 2–4 mm;

apices of inner phyllaries narrow, flexuous, flattened, entire or finely erose.
Heads

few–many in dense clusters at branch tips.

1–10+, borne at tips of main stem and branches.
Cypselae

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

pappi 9–11 mm.

brown, 5–6 mm, apical collars yellow, ca. 1 mm;

pappi 25–30 mm.
2n

= 34.

= 18 (as C. terrae-nigrae), 20 + 1B.

Cirsium palustre

Cirsium engelmannii
Phenology Flowering summer (Jul–Aug). Flowering spring–summer (May–Jul).
Habitat Marshes, wet forests Tallgrass prairies, old fields, roadsides, oak savannas, forest edges, in calcareous clay or rarely sandy soils
Elevation 10–800 m (0–2600 ft) 50–200 m (200–700 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
LA; OK; TX
[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 engelmannii occurs mostly in the blackland prairies of eastern Texas. It ranges northward into southeastern Oklahoma and eastward to northwestern Arkansas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 19, p. 110. FNA vol. 19, p. 117.
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. 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. 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
Synonyms Carduus palustris C. virginianum var. filipendulum, C. terrae-nigrae
Name authority (Linnaeus) Scopoli: Fl. Carniol. ed. 2, 2: 128. (1772) Rydberg: Fl. Rocky Mts., 1069. (1917)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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