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chardon mutique, dunce-nettle, horsetops, swamp thistle

Joanna's thistle

Habit Biennials, 30–230 cm; taproots fleshy. Perennials, 100–150 cm; caudices taprooted.
Stems

single, erect, villous with septate trichomes or glabrate, distally sometimes thinly tomentose;

branches few–many, ascending.

1, fleshy, erect, openly branched in distal 1/2, glabrous;

branches on distal stems several, ascending.

Leaves

ovate to broadly elliptic or obovate, 15–55 × 4–20 cm, deeply pinnatifid, to 7/8 to midribs, lobes linear to lanceolate, acute to acuminate, irregularly few toothed or lobed, main spines 2–3 mm, abaxial faces thinly tomentose or glabrate, villous with septate trichomes on the veins, adaxial faces thinly pilose;

basal usually absent at flowering, petioles spiny-winged, bases tapered;

principal cauline petiolate or sessile, gradually reduced distally, bases sometimes ± clasping, not decurrent;

distal cauline bractlike with narrowly linear lobes, often spinier than the proximal.

blades oblong, 10–50 × 6–12 cm, margins usually not strongly undulate, coarsely dentate or shallowly to deeply pinnatifid with 10–15 pairs of lobes, teeth or lobes ± closely spaced, not much overlapping, narrowly to broadly triangular, spiny-dentate or larger shallowly 3–5-lobed, main spines 2–12 mm, abaxial faces glabrous, adaxial glabrous;

basal present at flowering, petiolate or spiny winged-petiolate;

principal cauline many, well distributed, proximally ± winged-petiolate, distally sessile, gradually reduced, less divided, bases auriculate-claping and/or decurrent as spiny wings to 2 cm;

distal much reduced.

Peduncles

0–15 cm (sometimes overtopped by distal cauline leaves, not subtended by involucre-like ring of bracts).

0–2 cm Involucres green, ovoid to campanulate (not including spreading phyllary apices), 2.5–4 × 2.5–3.5 cm, appearing glabrous.

Involucres

ovoid to broadly cylindric or campanulate, 1.7–3 × 1–3 cm, arachnoid.

Corollas

lavender or purple (white), 16–32 mm, tubes 7–15 mm, throats 4.5–10 mm (noticeably wider than tubes), lobes 4–8 mm;

style tips 3.5–5 mm.

lavender-pink, 20–26 mm, tubes 5–8.5 mm, throats 5.2–8 mm, lobes linear, 9–10 mm;

style tips 3.5–4.2 mm, conspicuously exserted beyond corolla lobes.

Phyllaries

in 8–12 series, strongly imbricate, dull green with darker subapical patch, ovate (outer) to linear-lanceolate (inner), abaxial faces with narrow glutinous ridge, outer and middle appressed, bodies minutely spinulose, apices obtuse to acute, spines erect (sometimes appearing as spreading in dry specimens), 0–0.5 mm;

apices of inner phyllaries straight or ± flexuous, flattened.

in 5–7 series, unequal, outer longer than inner, bases short-appressed, abaxial faces without glutinous ridge, minutely scabridulous, apices green, thick, spreading to curved-ascending, proximally flattened, linear, spines stout, 5–12 mm;

outer entire or pinnately spiny, inner entire, scabridulous-ciliolate;

apices of inner flexuous, sometimes slightly expanded and minutely erose.

Heads

1–many in ± open corymbiform or paniculiform arrays.

several–many, erect or nodding, usually sessile or short-pedunculate, crowded in subcaptitate or short, spiciform clusters at branch tips, collectively forming open, paniculiform arrays.

Cypselae

dark brown, 4.5–5.5 mm, apical collars yellow, 0.3 mm;

pappi 12–20 mm.

dark brown, 4.5–5 mm, apical collars not differeniated;

pappi ca. 20 mm.

2n

= 20, 21, 22, 23, 30.

Cirsium muticum

Cirsium joannae

Phenology Flowering summer (Jul–Sep). Flowering summer (Aug–Sep).
Habitat Wet soil in meadows, prairies, marshes, swamps, bogs, open woods Hanging gardens with Lobelia, Abies, and Adiantum
Elevation 0–1500+ m (0–4900+ ft) 1700 m (5600 ft)
Distribution
from FNA
AL; AR; CT; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; NC; ND; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; MB; NB; NL; NS; ON; PE; QC; SK; SPM
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[BONAP county map]
Discussion

Cirsium muticum is very widely distributed across the eastern half of North America from the prairies of southeastern Saskatchewan across southern Canada to Newfoundland and south in the United States from North Dakota and Maine to southeastern Texas and northern Florida. It is more common in the northern half of this range and extends from the coastal plain to the Appalachian highlands. The widely scattered populations in coastal lowlands in the southern United States may be relicts of the glacial distribution of the species.

Cirsium muticum is known to hybridize with C. discolor (discussed thereunder) and C. flodmanii. Draining and modification of wetlands have affected populations of C. muticum in some areas.

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

Cirsium joannae is endemic to Zion National Park in southwestern Utah. It apears to be most closely related to C. rydbergii, which occurs in similar habitats in southeastern Utah and northeastern Arizona.

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

Source FNA vol. 19, p. 113. FNA vol. 19, p. 163.
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. 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
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. 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 muticus, C. muticum var. monticola
Name authority Michaux: Fl. Bor.-Amer. 2: 89. (1803) S. L. Welsh: in S. L. Welsh et al., Utah Fl. ed. 3, 168. (2003)
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