Cirsium arizonicum
Arizona thistle
(c) Jim Morefield, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Herb · Native
Cirsium arizonicum (Arizona thistle) is a native California herb in the Asteraceae family.
Arizona thistle is a native perennial herb found in southwestern desert regions in open rocky habitats at elevations of 1,500 to 2,500 meters. Flowering from June to September, this plant produces lavender to pink-purple flowers in heads 3 to 4 centimeters long with distinctive spiny involucres. Growing 20 to 150 centimeters tall with often multiple stems from a woody base, it develops thinly tomentose stems that become somewhat glabrous with age. Its lower leaves are large, oblong-obovate, and deeply lobed with spiny edges, measuring 10 to 20 centimeters long and tapering to spiny-winged leaf stalks. The fruit is small, 3.5 to 7 millimeters long, with a feathery pappus 17 to 28 millimeters in length.
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 native to California?
Yes. Cirsium arizonicum is native to California (recorded as native).
What plant family does Cirsium arizonicum belong to?
Cirsium arizonicum is in the Asteraceae family, genus Cirsium.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.