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few-leaf thistle, mountain thistle, Pacific fringe thistle, remote-leaf thistle, weak thistle

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

Habit Perennials, 20–150 cm, monocarpic; taprooted or polycarpic, perennating by runner roots. Annuals or biennials, 20–350 cm; taprooted.
Stems

usually 1, erect, finely arachnoid-tomentose, sometimes villous with septate trichomes below nodes;

branches 0–10+, slender, usually arising in distal 1/2, 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 linear-oblong to oblanceolate or elliptic, 7–30 × 1–15 cm, unlobed and spinulose to dentate or shallowly to deeply pinnatifid, lobes well separated, linear to triangular-ovate, dentate to deeply lobed, main spines 2–5 mm, slender, abaxial faces green to gray, thinly to densely arachnoid-tomentose, sometimes glabrate, sometimes villous with septate trichomes along veins, adaxial green, glabrous;

basal sometimes present at flowering, sessile or winged-petiolate;

principal cauline mostly in proximal 1/2, winged-petiolate or sessile, bases narrowed, sometimes auriculate;

distal well separated, progressively reduced, becoming bractlike, often unlobed or less deeply divided than the proximal, sometimes spinier than proximal, bases often distally expanded and auriculate-clasping.

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–)2–15 cm.

0–1(–30) cm.

Involucres

ovoid to hemispheric or campanulate, 1.5–2.5 × 1.5–3.5 cm, glabrous to arachnoid-floccose.

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

creamy white to purple, 18–28 mm, tubes 7–12 mm, throats 5–12 mm, lobes 3.5–7 mm, style tips 4–6 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 6–8 series, subequal to strongly imbricate, green, linear to obovate (outer) to linear (inner), abaxial faces with inconspicuous glutinous ridge;

outer and middle bases appressed, margins entire to spinulose-dentate or broad, scarious, lacerate-dentate, spines absent or ascending to spreading, 1–2 mm;

apices of inner sometimes flexuous or reflexed, narrow, flat, entire or expanded, scarious, and lacerate-dentate.

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

few–many, borne singly or in openly branched in corymbiform, racemiform, or paniculiform arrays on main stem and branches, sometimes also in distal axils, not closely subtended by clustered leaf bracts.

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

Cypselae

tan to dark brown, 4.5–5.5 mm, apical collars differentiated or not;

pappi 13–23 mm.

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

pappi 10–22 mm.

2n

= 32.

= 34.

Cirsium remotifolium

Cirsium brevistylum

Phenology Flowering spring–summer (Apr–Sep).
Habitat Coastal meadows, marshes, swamps, riparian woodlands, moist sites in coastal scrub, chaparral, coastal woodlands, mixed conifer-hardwood forests, or coniferous forests
Elevation 0–1000 m (0–3300 ft)
Distribution
from FNA
CA; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; MT; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 3 (3 in the flora).

Cirsium remotifolium occurs from the Coast Ranges and valleys of the Pacific Northwest to the western slopes of the Cascade and Klamath ranges, south in the California North Coast Ranges to the San Francisco Bay region. It is closely related to the C. clavatum complex of the Rocky Mountains region. Both have a similar growth habit and some forms variably express the character of broadly scarious, lacerate-toothed phyllary margins. Gray, in naming Cnicus carlinoides var. americanus, included as syntypes both California and Colorado specimens. F. Petrak (1917) treated both the West Coast plants and those of the Rocky Mountains as Cirsium subsect. Americana, recognizing C. remotifolium with several infraspecific taxa plus two other species, C. callilepis and C. amblylepis from the West Coast, and four additional species from the Rocky Mountains. A. Cronquist (1955) rejected Petrak’s subspecies, treating C. remotifolium in a restricted sense, limited to plants of Washington and Oregon without dilated phyllary tips, and circumscribed C. centaureae broadly to include the Rocky Mountains and West Coast plants with dilated phyllary tips. Because of the frequent presence of dilated phyllary tips in C. remotifolium in the restricted sense, Cronquist acknowledged the likelihood of past introgression with C. centaureae in the broad sense.

J. T. Howell (1960b) recognized three species: Cirsium remotifolium, C. acanthodontum, and C. callilepis, the latter with four varieties collectively corresponding to the West Coast representatives of C. centaureae (in the sense of Cronquist). Because of the great similarity of the various West Coast plants and their intergradation, I see no value in recognizing two or more species.

The West Coast and Rocky Mountains plants are clearly related, but are separated by the Great Basin region and there is little chance of current genetic interchange. As is often the case with American Cirsium, genetic enrichment from past hybridization with other nearby species within their respective areas has likely been fertile ground for evolutionary diversification. Different species have contributed genes in the Pacific states and in the Rockies. I have chosen to recognize two geographically-based species complexes, each with intergrading races here treated as varieties. I treat the West Coast plants as C. remotifolium and the Rocky Mountains plants as C. clavatum.

(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.)

Key
1. Phyllary margins ciliate with tiny spreading to recurved spines
var. rivulare
1. Phyllary margins unappendaged or dilated, scarious, and ± lacerate-toothed
→ 2
2. Phyllaries narrowly oblong or linear, often ± subequal, all or most without scarious-dilated margins
var. remotifolium
2. Phyllaries oblong to obovate, often strongly graduated, most or all with dilated, scarious, erose to lacerate-dentate margins
var. odontolepis
Source FNA vol. 19, p. 129. 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. 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. 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
Subordinate taxa
C. remotifolium var. odontolepis, C. remotifolium var. remotifolium, C. remotifolium var. rivulare
Synonyms Carduus remotifolius
Name authority (Hooker) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 655. (1838) Cronquist: Leafl. W. Bot. 7: 26. (1953)
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