Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Cirsium grahamii, Graham's Thistle

As with most thistles, Graham’s Thistle attracts many different insects including bees, wasps and butterflies. Here a bumblebee of the genus Bomus takes nectar from deep within the floral tubes. Cirsium grahamii Graham's Thistle blooms from July or August to September or even October. Flowering responds well to heavy summer monsoon rainfall. Cirsium grahamii Graham's Thistle has thick green, alternate leaves spiny over much of the leaf. The basal leaves remain green and healthy at bloom. Cirsium grahamii Graham's Thistle is relatively rare in the United States where it is limited in distribution to portions of Arizona and New Mexico. Plants prefer various high elevation habitats including pine forest opening, evergreen oak communities, closed grassy basins, meadows and other damp soil. Cirsium grahamii

Scientific Name: Cirsium grahamii
Common Name: Graham's Thistle
Also Called:

Family: Asteraceae, Sunflower Family

Synonyms: ()

Status: Native

Duration: Biennial or perennial

Size: To 3 feet (50-100 cm).

Growth Form: Forb/herb; generally 1 stem, erect, branches 0 to 4 ; all parts spiny; slightly arachnoid and puberulent to short-pilose, sometimes glabrate.

Leaves: Green; alternate along stem and branches; oblanceolate to oblong-elliptic; spiny over much of leaf; margins entire, coarsely dentate to deeply pinnatifid, lobes with or without teeth; basal leaves sessile or with narrow wings, basal leaves often remain green and healthy at bloom, basal leaves sometimes clasping.

Flower Color: Deep purple; large showy discoid flower heads slightly arachnoid or glabrous, single or clusters of 3 to 5; phyllaries lanceolate to linear, tipped with many long stiff spines; fruit is a cypsela (often mistaken as an achene.

Flowering Season: July or August to September or October, blooms following summer monsoons.

Elevation: 4,500 to 8,500 feet (1,372-2,591 m)

Habitat Preferences: Various high elevation habitats including pine forest openings, evergreen oak communities, closed grassy basins, meadows and damp soil.

Recorded Range: A rare thistle in the United States with a very limited distribution in the mountains of southeastern Arizona and southwestern New Mexico. Graham’s Thistle is also recorded in northern Mexico (Chihuahua, Durango, Sonora).

North America & US County Distribution Map for Cirsium grahamii.

U.S. Weed Information: No data available.

Invasive/Noxious Weed Information: In North America the genus Cirsium is listed as a Noxious Weed by the States of Arkansas and Iowa. Plants included here are invasive or noxious. ∗ See Comments section below.

Wetland Indicator: No data available.
Threatened/Endangered Information: No data available

Genus Information: In North America there are 91 species for Cirsium. Worldwide, The Plant List includes 481 accepted species names and a further 812 scientific names of infraspecific rank for the genus. The genus Cirsium was published by Philip Miller in 1754.

In the Southwestern United States: Arizona and New Mexico each have 19 species of genus, California has 27 species, Nevada has 16 species, Texas has 12 species, Utah has 23 species. All data approximate and subject to revision.

Comments: There is little botanical information for Graham’s Thistle which like many native thistles have limited geographic distribution and are not aggressive or noxious weed as notorious thistles. It appears to be more specialized in its habitat requirements as suggested by its extremely limited geographic range. Superficially similar in appearance to Wheeler’s Thistle, Cirsium wheeleri. According to The Flora of North America "It forms hybrid swarms with C. parryi and C. scariosum var. coloradense in the White Mountains of Arizona".

∗The genus Cirsium has received adverse notoriety because of the introduction of two thistles native to Europe and now widespread throughout North America. The Canadian Thistle, Cirsium arvense and and the Bull Thistle, Cirsium vulgare are both listed as noxious primarily by agricultural interests.

Most southwestern native thistles, including Graham's Thistle, are non-aggressive; non-invasive and beneficial as pollinators that have evolved to thrive without becoming weedy. Many native thistles are now threatened with some species at risk of extinction.

In Southwest Desert Flora also see; Arizona Thistle, Cirsium arizonicum, New Mexico Thistle, Cirsium neomexicanum, Mojave Thistle, Cirsium mohavense and Yellowspine Thistle, Cirsium ochrocentrum.

Importance to Wildlife, Birds and Livestock
Thistles of the genus Cirsium are regularly visited by many wildlife species such as small mammals, hummingbirds and nectar-feeding bats. Also the seeds are attractive to small mammals and finches such as American goldfinch.

Special Value to Native Bees, Butterflies and Insects
Thistles of the genus Cirsium are important as a group as they are frequently visited by pollinators such as Native bees, bumblebees and a very large numbers of insects and butterflies. "Monarch butterflies visit native thistle flowers more than any other wildflowers in some regions during their migration back to Mexico". They are also heavily used as food plants by the larvae of some Lepidoptera (butterfly) species. In addition to food Cirsium also provides nesting material and structure for Native bees and other insects.

To find out more about Butterflies and Moths of North America visit BAMONA.
For excellent information on invertebrate conservation visit The Xerces Society.

The genus Cirsium is derived from the Greek words kirsion "a kind of thistle" in turn from kirsos, "a swollen vein or welt," as thistles are used as a remedy for such issues. The genus Cirsium was published by Philip Miller in 1754.

The species epithet grahamii is named in honor of Virginia born James Duncan Graham (1799-1865), a West Point graduate and army officer. Mr. Graham is one of the founders of the army's topographical section and well known for his map making skills.


Date Profile Completed: 8/11/2012; updated 02/12/2020
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 02/06/2020) (for Cirsium) (for Cirsium)
The Plant List (2013). Version 1.1. Published on the Internet; (accessed 02/06/2020).
FNA 2006, Kearney and Peebles 1969, McDougall 1973 A Field Guide, SEINet
David J. Keil, FNA | Family List | FNA Vol. 19, 20 and 21 | Asteraceae, 27. Cirsium grahamii A. Gray, Smithsonian Contr. Knowl. 5(6): 102. 1853. Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford.
James Eckberg, Eric Lee-Mäder, Jennifer Hopwood, Sarah Foltz Jordan, and Brianna Borders; 2017. Native Thistles: A Conservation Practitioner’s Guide
'Cirsium grahamii', Wikipedia, The Free Encyclopedia, 1 February 2018, 04:12 UTC, [accessed 11 February 2020]
'Cirsium', Wikipedia, The Free Encyclopedia, 25 January 2020, 15:17 UTC, [accessed 7 February 2020]
SEINet synonyms, scientific names, geographic locations, general information
Etymology:Michael L. Charters California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology - (accessed 02/07/2020)