Cirsium arizonicum var. arizonicum
Arizona thistle
(c) Jim Morefield, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Perennial · Native
Cirsium arizonicum var. arizonicum (Arizona thistle) is a native California perennial in the Asteraceae family, recognized by high elevation, bright red flowers with long lobes.
Arizona thistle is a native perennial found in southern Sierra Nevada, White and Inyo Mountains in open forest and sagebrush scrub at elevations of 2,300 to 3,500 meters. Flowering from July to August, this plant produces bright red to red-pink flowers with long corolla lobes 13 to 18 millimeters long in distinctive thistle heads. Growing with erect stems that bear sharp spiny leaves, it develops a robust clumping habit typical of thistles. Its leaves range from unlobed to deeply divided, with main leaf spines 2 to 15 millimeters long that provide a distinctive defensive structure. The flower's intricate design features a corolla tube 7 to 12 millimeters long with a throat 2 to 5 millimeters wide, creating an elegant botanical profile.
Identification and appearance
Key characters: 10 sympatric species; high elevation, bright red flowers with long lobes
Habitat and range
Habitat: Open forest, sagebrush scrub
Elevation: 2300-3500 m
Outside California: to Utah, New Mexico
Bloom period
Cirsium arizonicum var. arizonicum blooms Jul-Aug.
How to tell it apart
vs Carduus: Cirsium has fluffy, feathery seed tufts; Carduus has rough bristles or no pappus and continuous spiny wings down the stem.; vs Silybum: Cirsium leaves are plain green; Silybum has bright white marbling along the leaf veins.; vs Sonchus: Cirsium has thistle-type flowers with spine-tipped bracts; Sonchus has dandelion-like flowers and milky sap.; vs Cynara: Cirsium heads are 1-6 cm across; Cynara heads are massive (4-15 cm, tennis ball sized) with fleshy bases.; vs Centaurea: Cirsium has linear bracts without appendages; Centaurea bracts have fringed or comb-like tips.
Frequently asked questions
Is Cirsium arizonicum var. arizonicum native to California?
Yes. Cirsium arizonicum var. arizonicum is native to California (recorded as native).
When does Cirsium arizonicum var. arizonicum bloom?
Cirsium arizonicum var. arizonicum blooms Jul-Aug.
What plant family does Cirsium arizonicum var. arizonicum belong to?
Cirsium arizonicum var. arizonicum is in the Asteraceae family, genus Cirsium.
What habitat does Cirsium arizonicum var. arizonicum grow in?
Cirsium arizonicum var. arizonicum grows in Open forest, sagebrush scrub.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.