Cirsium neomexicanum
Desert thistle
(c) Eric Knight, some rights reserved (CC BY), uploaded by Eric Knight · licence
Family: Asteraceae · Type: Herb · Native
Cirsium neomexicanum (Desert thistle) is a native California herb in the Asteraceae family, recognized by features are head shape, flower color, and spine size.
Desert thistle is a California native biennial found in eastern Mojave Desert and northwestern Sonoran Desert regions in canyons, slopes, and roadsides at elevations of 800 to 2,100 meters. Flowering from April to May, this plant produces white to pale lavender or pink flowers in heads 2.5 to 5 centimeters wide, forming open, flat-topped clusters. Growing 40 to 290 centimeters tall with a single stem and a few ascending branches, it is covered in white cobwebby tomentose hairs. Its large lower leaves are oblong-elliptic to oblanceolate, persistently gray-tomentose, with rigidly spreading lobes and main spines 5 to 15 millimeters long. The fruit is 5 to 6 millimeters long with a pappus 15 to 20 millimeters in length.
Identification and appearance
Key characters: 5 sympatric species; diagnostic features are head shape, flower color, and spine size
Habitat and range
Habitat: Canyons, slopes, roadsides
Elevation: 800-2100 m
Outside California: to Colorado, New Mexico
Bloom period
Cirsium neomexicanum blooms Apr-May.
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 neomexicanum native to California?
Yes. Cirsium neomexicanum is native to California (recorded as native).
When does Cirsium neomexicanum bloom?
Cirsium neomexicanum blooms Apr-May.
What plant family does Cirsium neomexicanum belong to?
Cirsium neomexicanum is in the Asteraceae family, genus Cirsium.
What habitat does Cirsium neomexicanum grow in?
Cirsium neomexicanum grows in Canyons, slopes, roadsides.
Related species
Other California species in the same genus, family, or bioregion.
- Cirsium occidentale — Cobweb thistle
- Cirsium occidentale var. californicum — California thistle
- Cirsium occidentale var. candidissimum — Snowy thistle
- Cirsium occidentale var. compactum — Compact cobwebby thistle
- Cirsium occidentale var. coulteri — Coulter's thistle
- Cirsium occidentale var. lucianum — Cuesta ridge thistle
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.