Cirsium wrightii (Wright's marsh thistle)

Cirsium wrightii (Wright's marsh thistle)

Photograph by Bob Sivinski
Scientific Name with Author

Cirsium wrightii A. Gray



Common Name
Wright's marsh thistle
Rare Plant Conservation Scorecard Summary
Overall Conservation Status Documented Threats Actions Needed

Water management/use, Livestock ranching/farming

Protection/exclosures for existing spring habitat. Population trend monitoring.


Robust biennial or monocarpic perennial; stem strict, 1-2.5 m tall; basal leaves ample, succulent, 30 cm or more long, sinuate or pinnatifid, weakly prickly with short black spines, nearly glabrous, the thin weblike wool tardily deciduous; stem leaves similar, sessile, strongly decurrent, gradually reduced in size up the stem; heads terminating thin branches in naked panicles, hemispherical, 2-3 cm across; phyllaries small, somewhat glandular with papillose projections on upper surface; outer phyllaries subulate, cuspidate-tipped; corollas white or pink; style tips about 3 mm long. Flowers August to October.

Similar Species

Cirsium wrightii differs from C. texanum in being an obligate wetland species with nearly glabrous leaves and stem and thick succulent leaves. It is tall (up to 2.5 m), and has a strict growth form.


Extant in New Mexico in Eddy, Chaves, Guadalupe, Otero, and Socorro counties.  Presidio County, Texas; Chihuahua, Mexico.


Wet, alkaline soils in spring seeps and marshy edges of streams and ponds; 1,130-2,600 m (3,450-8,500 ft).


C. wrightii sometimes occurs with the threatened Cirsium vinaceum in the Sacramento Mountains where a few hybrids between these rare taxa have been observed. It also occasionally occurs with the threatened Helianthus paradoxus in the Pecos River valley.

Cirsium wrightii was found extant in the state of Chihuahua, Mexico in 2018, at El Ojo Vareleño, a hot springs spa in the town of Casas Grandes. An additional 4 cienegas were surveyed in the states of Sonora and Chihuahua in Mexico between 2017 and 2019, but no additional population were found.

A 2003 collection of Cirsium wrightii from Presidio County, TX, was confirmed by Guy Nesom in 2018.

Conservation Considerations

The type location for this species is, "Around springs near San Bernardino, on the borders of New Mexico and Sonora, Oct." This appears to be a location in Cochise County, Arizona, but this taxon has not been relocated in that county. An old specimen collected at Lake Valley in southern Sierra County is stored at the U.S. National Herbarium. Suitable spring seeps no longer occur there and this population also is likely extirpated. Known extant populations are widely disjunct. Desert springs and cienegas are susceptible to drying-up, or being diverted. Populations in the city of Roswell, Chavez County, at Lake Valley, Sierra County, and at San Bernardino Cienega in Arizona appear to be extirpated.

Introduction of insects as biological control for weedy thistles may pose a grave hazard for non-weedy thistle species.

Important Literature

Gray, A. 1853. Plantae Wrightianae 2:101. [Original description]

Gray, A. 1874. Proceedings of the American Academy of Science 10:41.

Nesom, Guy L. 2018.  Cirsium wrightii (Asteraceae) in the Texas flora. Phytoneuron 2018-63: 1–6.

Roth, D. 2020.  Wright's marsh thistle (Cirsium wrightii) 2017 - 2020 monitoring report . Blue Hole and Ballpark Ciénegas, Santa Rosa, NM.  Unpublished report by the EMNRD-Forestry Division for the USFWS, Region 2.

Sánchez Escalante José Jesús, Jesús Pablo Carrillo León and Jorge Orel Cruz-Zagasta. 2019. Surveys for Cirsium wrightii and other rare plants (Graptopetalum bartramii, Pediomelum pentaphyllum, Pectis imberbis, Leucosyris blepharophylla, and Eryngium sparganophyllum) in northeastern Sonora and northern Chihuahua, Mexico.  Final report. Universidad de Sonora, Herbario USON Rosales y Blvd. Luis Encinas Johnson, Col. Centro Hermosillo, Sonora, México. U.S. Fish and Wildlife Service Section 6 Contract 2017-2019-01

Sivinski, R.C. 1996. Wright's marsh thistle, Cirsium wrightii. Section 6 progress report, segment 10, for U.S. Fish and Wildlife Service, New Mexico Ecological Services Field Office, Albuquerque.

Sivinski, R.C. 2012. Cirsium wrightii - Wright's marsh thistle: a 2012 population assessment. Unpublished report prepared for EMNRD-Forestry Division, Santa Fe, NM. RCS Southwest, Santa Fe, NM.

Sivinski, R.C. 2016. New Mexico thistle identification guide. Prepared for the Native Plant Society of New Mexico, Albuquerque. Available at:

Information Compiled By
Patricia Barlow-Irick 1999; last updated 2021

For distribution maps and more information, visit Natural Heritage New Mexico