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Anderson's thistle, rose thistle

Brewer's thistle, California swamp or Douglas' thistle, Douglas' thistle, swamp thistle

Habit Perennials (but often appearing biennial), (15–)40–70(–100) cm; rootstocks producing erect, taprooted caudices and rosettes. Biennials or short-lived monocarpic perennials, 60–250 cm; taprooted.
Stems

usually 1, erect, subglabrous to puberulent and/or tomentose;

branches 0–several, stiffly ascending.

1–several, erect or ascending, densely gray-tomentose;

branches few–many, ascending to spreading.

Leaves

blades ± elliptic, 8–35 × 4–8 cm, divided about halfway to midveins, lobes spreading, triangular, coarsely dentate or with a few broad lobes, obtuse to acute, main spines 1–5 mm, abaxial faces green or gray, thinly tomentose, adaxial green and glabrous to sparingly pilose;

basal often present at flowering, spiny winged-petiolate;

main cauline reduced distally, bases clasping;

distal much reduced, linear-oblong, usually less deeply lobed and often spinier than proximal.

blades oblong-elliptic to obovate, 10–60 × 2–15 cm, unlobed or shallowly to deeply pinnatifid, lobes lanceolate to ovate-triangular, ascending to spreading, entire to coarsely dentate or lobed, main spines slender to stout, 2–30 mm, faces densely gray-tomentose, rarely glabrate;

basal present at flowering, petiolate;

principal cauline well distributed, proximal winged-petiolate, distal sessile, bases auriculate-clasping or decurrent as a spiny wing 1–3 cm;

distalmost well separated, bractlike.

Peduncles

0–20 cm.

0–4(–8) cm.

Involucres

broadly cylindric to narrowly campanulate, 3–5 × 2–4 cm, loosely arachnoid or ± glabrous, finely short-ciliate.

ovoid to hemispheric, 1.5–3 cm, 2–4.5 cm diam, loosely arachnoid on phyllary margins or glabrate.

Corollas

red to reddish purple, 30–45 mm, tubes 10–20 mm, throats 10–16 mm, lobes 9–11 mm;

style tips 3.5–5 mm.

rose-purple (white or pinkish-tinged), 18–21 mm, tubes 8–9 mm, throats 5–6 mm (abruptly expanded), lobes 5–6 mm;

style tips 3–4.5 mm.

Phyllaries

in 6–8 series, imbricate, outer green, inner purple to red, linear-lanceolate (outer) to linear (inner), abaxial faces without glutinous ridge;

outer and mid bodies short, appressed, entire or spinulose-ciliate, apices long-spreading to ascending, entire or spinulose-ciliate or rarely with expanded, fringed appendages, spines straight, weak, 1–3 mm;

apices of inner red to purple, straight or rarely twisted, long, flat, entire.

in 6–8 series, imbricate, often with dark purple patch near tip, ovate-lanceolate (outer) to linear-lanceolate (inner), abaxial faces with linear to elliptic glutinous ridge;

outer and middle appressed, entire, spines spreading, 1–9 mm;

apices of inner often purple-tinged, often flexuous, flattened, spineless, scabrid.

Heads

1–6, borne singly or in corymbiform, racemiform, or spiciform arrays.

10–many, often crowded at branch tips, collectively forming paniculiform arrays.

Cypselae

brown, 6–7 mm, apical collars narrow;

pappi 25–40 mm.

dark brown to black, 5–6 mm, apical collars not differentiated;

pappi 15–20 mm.

2n

= 32, 64.

Cirsium andersonii

Cirsium douglasii

Phenology Flowering summer (Jul–Sep).
Habitat Moist to dry soils, openings in montane woodlands, montaine coniferous forests, aspen groves
Elevation 1100–2900 m (3600–9500 ft)
Distribution
from FNA
CA; ID; NV
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Cirsium andersonii grows in the Cascade Range of northern California south through the Sierra Nevada of eastern California and western Nevada. It has been reported from the mountains of southwestern Idaho, but I have not seen specimens from there.

Heads of Cirsium andersonii are actively visited by hummingbirds as well as a variety of insects (P. L. Barlow-Irick 2002).

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

Varieties 2 (2 in the flora).

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

Key
1. Distal cauline leaves with larger spines mostly less than 7 mm
var. breweri
1. Distal cauline leaves with larger spines usually 7–20 mm
var. douglasii
Source FNA vol. 19, p. 145. FNA vol. 19, p. 133.
Parent taxa Asteraceae > tribe Cardueae > Cirsium Asteraceae > tribe Cardueae > Cirsium
Sibling taxa
C. altissimum, 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. 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. 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. douglasii var. breweri, C. douglasii var. douglasii
Synonyms Cnicus andersonii
Name authority (A. Gray) Petrak: Bot. Tiddsskr. 31: 68. (1911) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 643. (1838)
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