Cirsium grahamii, Graham's Thistle
Scientific Name: Cirsium grahamii
Common Name: Graham's Thistle
Family: Asteraceae, Sunflower Family
Synonyms: ( )
Size: To 3 feet.
Growth Form: Forb/herb; erect, single stem, all parts spiny.
Leaves: Green; oblanceolate to oblong-elliptical, 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; single flower head or clusters of 3 to 5, bracts (phyllaries subtending flower head are tipped with many long stiff spines; fruit is an achene.
Flowering Season: August to October, blooms following summer monsoon rainfall.
Elevation: 6,500 to 7,500 feet, a narrow range of elevation.
Habitat Preferences: Various high elevation habitats including pine forest openings, evergreen oak communities, closed grassy basins, meadows and other damp areas.
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: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available
Comments: There is little botanical information for Graham’s Thistle, which, like many native thistles have limited geographic distribution and are not an 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.In Southwest Desert Flora also see; Arizona Thistle, Cirsium arizonicum, New Mexico Thistle, Cirsium neomexicanum and Yellowspine Thistle, Cirsium ochrocentrum.