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

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 grahamiiGraham's Thistle has large showy deep purple florets subtended by attractive greenish bracts or phyllaries. In the photo note the array of insects about the floral parts. Cirsium grahamiiGraham's Thistle blooms from July or August to September or even October. Flowering responds well to heavy summer monsoon rainfall. Cirsium grahamiiGraham's Thistle has thick green, alternate leaves spiny over much of the leaf. The basal leaves remain green and healthy at bloom. Cirsium grahamiiGraham'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.
Growth Form: Forb/herb; slender taproots; erect; single stem; all parts spiny; thinly arachnoid and puberulent to short-pilose, sometimes glabrate.
Leaves: Green; alternate; oblanceolate to oblong-elliptic; spiny over much of leaf; margins entire, coarsely dentate or pinnatifid, lobes with or without teeth; basal leaves sessile or with narrow wings, basal leaves remain green and healthy at bloom.
Flower Color: Deep purple; large showy discoid flower heads; single or clusters, 3 to 5; phyllaries lanceolate to linear, tipped with many long stiff spines; cypsela tan with dark speckles to dark purplish brown; fruit an achene.
Flowering Season: July or August to September or October, blooms following summer monsoon rainfall.
Elevation: 4,500 to 8,500 feet.

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

Recorded Range: A rare thistle in the United States with a very limited distribution in northern and southern Arizona and central New Mexico. Graham’s Thistle is also recorded in northern Mexico.

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.

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

Genus Information: In North America there are more than 90 species and 113 recorded taxa overall for Cirsium. World wide, The Plant List includes 481 accepted species names and includes a further 812 of infraspecific rank for the genus.

In the Southwestern United States: Arizona has 19 species of Cirsium, California has 26 species, Nevada has 16 species, New Mexico has 19 species, Texas has 12 species, Utah has 23 species. All data is approximate and subject to taxonomic changes.

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. Like most thistles, Graham’s Thistle attracts many different insects including bees, wasps and butterflies. Superficially similar in appearance to Wheeler’s Thistle, Cirsium wheeleri.

The genus Cirsium has achieved adverse notoriety from two introduced European thistles now wide-spread throughout North America; Canadian thistle, Cirsium arvense is listed as noxious in 33 states and Bull Thistle, Cirsium vulgare, is also a noxious weed. However most southwestern native thistles, including Arizona Thistle, are non-aggressive; non-invasive species that have evolved to thrive without becoming weedy in their respective select geographic southwestern ecosystems. 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 and Yellowspine Thistle, Cirsium ochrocentrum.

Special Value to Native Bees, Birds and Insects

As with most thistles, Graham’s Thistle attracts many different insects including bees, wasps and butterflies. The Xerces Society for Invertebrate Conservation acknowledges in their 2017 publication "Native Thistles: A Conservation Practitioner's Guide" that "native thistles are misunderstood and wrongly maligned group of wildflowers..." when in fact native thistles provide resources for many species of bees, butterflies and other wildlife which rely heavily on these species plants. "Monarch butterflies visit native thistle flowers more than any other wildflowers in some regions during their migration back to Mexico".


The genus Cirsium is from the Greek word "kirsion" "a kind of a thistle" which is translated from the Greek word "kirsos" meaning "swollen vein or welt"; a reference to their remedy against swollen veins and welts as thistles were quite often used as a remedy for these types of ailments.

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, 07/25/2015, updated 11/11/2017
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 10/25/2017)
The Plant List (2013). Version 1.1. Published on the Internet; (accessed 10/25/2017).
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
SEINet synonyms, scientific names, geographic locations, general information, (accessed 11/11/2017).
The Smithsonian Institution; National Portrait Gallery (accessed 11/11/2017).
Wikipedia contributors, 'Cirsium', Wikipedia, The Free Encyclopedia, 8 August 2017, 05:20 UTC, [accessed 11 November 2017]