FNA: Cirsium wrightii

	Cirsium wrightii
	Wright's Marsh thistle, Wright's thistle
Habit	Biennials or monocarpic perennials, 100–300 cm; taproots short with many slender, fibrous lateral roots.
Stems	usually 1, erect, glabrous to ± tomentose; branches many, usually restricted to distal part of stem, ascending.
Leaves	blades oblong to elliptic, 10–60 × 5–20 cm, unlobed and merely spinulose to irregularly dentate or shallowly to deeply pinnatifid, lobes ± broadly triangular, separated by wide sinuses, obtuse to acute, sometimes coarsely toothed or lobed, main spines slender, 1–3 mm, faces thinly arachnoid, soon glabrescent; basal often present at flowering, petioles slender, ± winged; cauline progressively reduced, proximal petiolate, mid and distal sessile, long-decurrent; distalmost linear to narrowly elliptic, bractlike, spinulose to irregularly dentate or shallowly lobed.
Peduncles	slender, 1–15 cm.
Involucres	ovoid to hemispheric, 1–2 × 1–2 cm, thinly arachnoid, glabrate.
Corollas	white to pink-purple, 19–21 mm, tubes 9–10 mm, throats 4–4.5 mm, lobes 5–7 mm; style tips 2–3.5 mm.
Phyllaries	in 8–9 series, strongly imbricate, green, lanceolate (outer) to linear (inner), abaxial faces with prominent glutinous ridge; outer and middle appressed, bodies entire, apices acute, spines spreading, slender, ca. 1 mm; apices of inner often flexuous, acuminate, flat, scabrid-ciliolate.
Heads	many, in openly paniculiform arrays, borne singly at tips of peduncles.
Cypselae	brown, ca. 4.5 mm, apical collars stramineous, 0.2 mm; pappi 15–16 mm.

	Cirsium wrightii
Phenology	Flowering summer–fall (Aug–Oct).
Habitat	Springs, seeps, marshes, stream banks, often in alkaline soil
Elevation	1100–2600 m (3600–8500 ft)
Distribution	AZ; NM; TX; Mexico (Chihuahua, Sonora) [BONAP county map]
Discussion	Of conservation concern. Wright’s thistle occurs from the mountains of south-central New Mexico eastward to the cienegas of the adjacent southwestern Great Plains. Cirsium wrightii is listed by the state of New Mexico as a species of concern. The one known site in Cochise County, Arizona, is apparently historic. Hybrids are known between Cirsium wrightii and C. vinaceum in the Sacramento Mountains of New Mexico. I have observed hummingbird visits to the heads of both species, though C. wrightii shows none of the apparent adaptations to hummingbirds (P. L. Barlow-Irick 2002) that are seen in such taxa as C. occidentale var. candidissimum, C. andersonii, and C. arizonicum. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 19, p. 131.
Parent taxa	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. 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
Name authority	A. Gray: Smithsonian Contr. Knowl. 5(6): 101. (1853)
Web links	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Cirsium wrightii

Wright's Marsh thistle, Wright's thistle

Habit

Biennials or monocarpic perennials, 100–300 cm; taproots short with many slender, fibrous lateral roots.

Stems

usually 1, erect, glabrous to ± tomentose;

branches many, usually restricted to distal part of stem, ascending.

Leaves

blades oblong to elliptic, 10–60 × 5–20 cm, unlobed and merely spinulose to irregularly dentate or shallowly to deeply pinnatifid, lobes ± broadly triangular, separated by wide sinuses, obtuse to acute, sometimes coarsely toothed or lobed, main spines slender, 1–3 mm, faces thinly arachnoid, soon glabrescent;

basal often present at flowering, petioles slender, ± winged;

cauline progressively reduced, proximal petiolate, mid and distal sessile, long-decurrent;

distalmost linear to narrowly elliptic, bractlike, spinulose to irregularly dentate or shallowly lobed.

Peduncles

slender, 1–15 cm.

Involucres

ovoid to hemispheric, 1–2 × 1–2 cm, thinly arachnoid, glabrate.

Corollas

white to pink-purple, 19–21 mm, tubes 9–10 mm, throats 4–4.5 mm, lobes 5–7 mm;

style tips 2–3.5 mm.

Phyllaries

in 8–9 series, strongly imbricate, green, lanceolate (outer) to linear (inner), abaxial faces with prominent glutinous ridge;

outer and middle appressed, bodies entire, apices acute, spines spreading, slender, ca. 1 mm;

apices of inner often flexuous, acuminate, flat, scabrid-ciliolate.

Heads

many, in openly paniculiform arrays, borne singly at tips of peduncles.

Cypselae

brown, ca. 4.5 mm, apical collars stramineous, 0.2 mm;

pappi 15–16 mm.

Cirsium wrightii

Phenology

Flowering summer–fall (Aug–Oct).

Habitat

Springs, seeps, marshes, stream banks, often in alkaline soil

Elevation

1100–2600 m (3600–8500 ft)

Distribution

AZ; NM; TX; Mexico (Chihuahua, Sonora)

[BONAP county map]

Discussion

Of conservation concern.

Wright’s thistle occurs from the mountains of south-central New Mexico eastward to the cienegas of the adjacent southwestern Great Plains. Cirsium wrightii is listed by the state of New Mexico as a species of concern. The one known site in Cochise County, Arizona, is apparently historic.

Hybrids are known between Cirsium wrightii and C. vinaceum in the Sacramento Mountains of New Mexico. I have observed hummingbird visits to the heads of both species, though C. wrightii shows none of the apparent adaptations to hummingbirds (P. L. Barlow-Irick 2002) that are seen in such taxa as C. occidentale var. candidissimum, C. andersonii, and C. arizonicum.

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

Source

FNA vol. 19, p. 131.

Parent taxa

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. 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

Name authority

A. Gray: Smithsonian Contr. Knowl. 5(6): 101. (1853)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

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Cirsium wrightii

Cirsium wrightii