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chardon de Flodman, Flodman's thistle, prairie thistle

cluster thistle, Indian or cluster or short-style thistle, Indian thistle, short-style thistle

Habit Perennials 30–140 cm; horizontal runner roots that produce root sprouts. Annuals or biennials, 20–350 cm; taprooted.
Stems

1–several, erect, gray- or white-tomentose;

branches 0–few, ascending.

usually 1, erect, simple or branched in distal 1/2, loosely to densely villous or viscid-pilose with jointed trichomes, often arachnoid below heads;

branches 0–many, ascending.

Leaves

blades oblong-oblanceolate to narrowly elliptic, 4–40 × 1–10 cm, bases usually not decurrent, finely spiny-toothed and undivided to coarsely toothed or deeply pinnatifid, lobes broadly triangular to linear-lanceolate, often revolute-margined, main spines 1–7 mm, abaxial faces white-tomentose, adaxial faces green, thinly tomentose, ± glabrate;

basal usually absent or withered at flowering, winged petiolate;

principal cauline proximally winged-petiolate, distally sessile, well distributed, gradually reduced, bases usually not decurrent;

distal cauline well developed.

blades oblong to elliptic or oblanceolate, 15–35 × 2–10 cm, flat to ± undulate, coarsely dentate to shallowly pinnatifid, lobes broadly triangular, spinulose to spiny-dentate or shallowly lobed, main spines slender, 3–7 mm, abaxial faces thinly gray-tomentose, villous along major veins, sometimes glabrescent, adaxial sparsely villous or viscid-pilose along midveins with jointed trichomes;

basal often absent at flowering, spiny winged-petiolate;

principal cauline well distributed, gradually reduced, proximal winged-petiolate, mid and distal sessile, bases clasping or short-decurrent;

distal moderately to strongly reduced, often spinier than the proximal.

Peduncles

0–5 cm (elevated above distal leaves).

0–1(–30) cm.

Involucres

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

hemispheric to campanulate, 2.5–3.5 cm, 2.5–4 cm diam., loosely to densely arachnoid, phyllaries connected by long septate or non-septate trichomes.

Corollas

purple (white), 23–36 mm, tubes 12–15 mm, throats 6–8.5 mm, lobes 5–9 mm;

style tips 4–7 mm.

white to pink or purple, very slender, 20–25 mm, tubes 10–17 mm, throats 4–5 mm, lobes filiform with knoblike tips, 3–5 mm;

style tips 2–4 mm, included or exserted (only 1–2 mm beyond corolla lobes).

Phyllaries

in 7–12 series, strongly imbricate, greenish with subapical darker central zone, ovate or lanceolate (outer) to linear (inner), abaxial faces with prominent glutinous ridge;

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

apices of inner spreading, flexuous, narrow, flattened, finely serrulate, ± scabrous.

radiating in 5–10 series, subequal, green, linear-acicular, outermost margins sometimes spiny-fringed, otherwise all entire or minutely serrulate, abaxial faces without glutinous ridge;

outer and mid bases short-appressed, apices stiffly radiating to ascending, long, very narrow, spines straight, slender, 3–5 m;

apices of inner straight, flat.

Heads

erect, borne singly and terminal on main stem and branches, or few in corymbiform arrays from distal axils (not subtended by ring of spiny-margined bracts).

1–many, ± erect, usually crowded in subcapitate to tight corymbiform arrays, closely subtended by clustered ± leafy bracts.

Cypselae

light brown, 3–5 mm, apical collars stramineous, 0.5–1 mm;

pappi (white or tawny) 20–30 mm.

brown, 3–4.5 mm, apical collars stramineous, 0.2 mm;

pappi 10–22 mm.

2n

= 22, 24.

= 34.

Cirsium flodmanii

Cirsium brevistylum

Phenology Flowering summer (Jun–Sep). Flowering spring–summer (Apr–Sep).
Habitat Tallgrass, mixedgrass, shortgrass prairies, meadows, pastures, often in damp soil Coastal meadows, marshes, swamps, riparian woodlands, moist sites in coastal scrub, chaparral, coastal woodlands, mixed conifer-hardwood forests, or coniferous forests
Elevation 100–2400 m (300–7900 ft) 0–1000 m (0–3300 ft)
Distribution
from FNA
CO; IA; IL; KS; MI; MN; MT; ND; NE; SD; WI; WY; AB; MB; ON; QC; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; MT; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Cirsium flodmanii ranges from Saskatchewan and Alberta south through the northern Great Plains and intermountain valleys of Montana and Wyoming to northeastern Colorado and east through the prairies to Minnesota and Iowa, and in widely scattered locations eastward to northern Illinois, southern Wisconsin, southern Ontario, and southern Quebec. It is known to hybridize with C. muticum and C. undulatum. Hybrids between C. flodmanii and C. undulatum are highly sterile with numerous meiotic irregularities (S. Dabydeen 1987).

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

Cirsium brevistylum occurs in the coast ranges and adjacent coastal slope from southwestern British Columbia to southern California. In the Pacific Northwest its range extends inland to the northern Rocky Mountains of southern British Columbia, Idaho, and northwestern Montana, and the Blue and Wallowa ranges of eastern Oregon. It is absent from the central and southern Cascade Range.

In older literature the name Cirsium edule was widely misapplied to this species. A. Cronquist (1953) pointed out that the type of C. edule has corolla and style features quite different from those of the plants that had been called by that name and established the name C. brevistylum, based upon the notably short styles of this species. Hybrids of C. brevistylum with C. edule have been named C. ×vancouveriense R. J. Moore & C. Frankton.

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

Source FNA vol. 19, p. 120. FNA vol. 19, p. 148.
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. 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
C. altissimum, C. andersonii, C. andrewsii, C. arizonicum, C. arvense, C. barnebyi, C. brevifolium, 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. 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 flodmanii, C. oblanceolatum
Name authority (Rydberg) Arthur: Torreya 12: 34. (1912) Cronquist: Leafl. W. Bot. 7: 26. (1953)
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