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slough thistle

Kamchatka thistle

Habit Annuals or biennials, (60–)100–300 cm; taprooted. Perennials, 25–200 cm; rhizomes stout.
Stems

usually 1, erect, stout, (hollow, 2–10 cm diam. at base), openly branched distally, thinly arachnoid, villous with jointed trichomes, at least proximally.

single, erect, ± glabrous to variably tomentose with coarse, jointed, multicellular trichomes and/or fine smooth trichomes;

branches 0–few, ascending.

Leaves

blades elliptic to broadly oblanceolate, 15–70 × 30–150+ cm, flat, pinnatifid 1/2–2/3 distance to midvein, larger usually with broad sinuses, lobes broad, few lobed or dentate, main spines 3–8 mm, abaxial faces gray-tomentose, adaxial thinly arachnoid-tomentose, sometimes midveins with jointed trichomes;

basal present or withered at flowering, winged-petiolate;

principal cauline sessile, progressively reduced distally, bases clasping or short-decurrent 1–2 cm;

distal cauline reduced, becoming bractlike, sometimes spinier than proximal.

blades broadly elliptic to obovate, 15–40 × 7–15 cm, subentire to coarsely pinnatifid 1/2–2/3 length to midveins, lobes few, lanceolate to triangular-ovate, shallowly lobed or dentate, main spines bristlelike, fine, innocuous, 3–6 mm, abaxial glabrous to villous with septate trichomes or thinly tomentose with jointed trichomes, adaxial faces glabrous or loosely tomentose along midveins;

basal usually absent at flowering, winged-petiolate, ciliate with fine, flexible spines to 8 mm;

principal cauline well distributed, little reduced, bases broadly tapered to clasping, short-decurrent;

distalmost moderately reduced.

Peduncles

0–15 cm.

0–1 cm.

Involucres

ovoid to campanulate, 1.5–3 × 1.5–3 cm, ± glabrous.

hemispheric to broadly campanulate, 1.5–2 × 2–3.5 cm, ± densely arachnoid.

Style

tips 3–4 mm.

Corollas

pale rose-purple (white), 19–26 mm, tubes 9–12 mm, throats 4–6 mm, lobes 5–9 mm;

style tips 3.5–4.5 mm.

pink to purple, 16–17 mm, tubes 8–9 mm, throats 3–4 mm, lobes 4–5 mm.

Phyllaries

in 5–7 series, weakly unequal, dark green to brownish, lanceolate (outer) to linear (inner), abaxial faces without (or with very obscure) glutinous ridge;

outer and middle appressed or apices spreading, at least outer irregularly spiny-fringed, finely serrulate, spines slender, 3–5 mm;

apices of inner erect, abaxial faces gray-tomentose, ± twisted.

in 5–7 series, subequal, green or tinged purple, linear or linear-lanceolate, abaxial faces without glutinous ridge, outer and middle erect or outer spreading, entire, apices long-acuminate, spines 0–2 mm;

apices of inner phyllaries straight or flexuous, flat.

Heads

1–several at branch tips, closely subtended by clustered leafy bracts or not, collectively forming open, corymbiform or paniculiform arrays.

1–few, in spiciform or subcapitate arrays.

Cypselae

dark brown, 5–5.5 mm, collars narrow, ± stramineous;

pappi 15–20 mm.

brown, 4 mm, apical collars not well differentiated;

pappi 12–15 mm.

2n

= 32.

= 68 (Japan).

Cirsium crassicaule

Cirsium kamtschaticum

Phenology Flowering spring (Apr–Jun). Flowering summer (Jul–Sep).
Habitat Freshwater marshes, canal banks Meadows and tundra
Elevation 5–100 m (0–300 ft) 0–100 m (0–300 ft)
Distribution
from FNA
CA
[BONAP county map]
from FNA
AK; Asia (Japan, Siberia)
[BONAP county map]
Discussion

Cirsium crassicaule is known only from a few sites in the San Joaquin Valley. Some populations are threatened by habitat modification and development pressures.

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

Cirsium kamtschaticum grows in the western Aleutian Islands, eastern Siberia, Sahkalin, the Kurile Islands and northern Japan (Hokkaido). It is one of only two species of the genus that have native populations in the Old World and the flora area. Neither reaches the North American mainland.

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

Source FNA vol. 19, p. 132. FNA vol. 19, p. 111.
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. 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
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. 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 crassicaulis
Name authority (Greene) Jepson: Fl. W. Calif., 506. (1901) Ledebour ex de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 644. (1838)
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