Cirsium cymosum
Peregrine thistle
(c) Arvel Hernandez, some rights reserved (CC BY), uploaded by Arvel Hernandez · licence
Family: Asteraceae · Type: Herb · Native
Cirsium cymosum (Peregrine thistle) is a native California herb in the Asteraceae family.
Peregrine thistle is a California native perennial herb found in rocky and open areas at moderate elevations. Flowering from May to September, this plant produces dull white flowers in clusters with heads 2 to 3 centimeters wide, emerging from delicate, cobwebby stems. Growing 2.5 to 12 decimeters tall with generally branched stems, it develops distinctive runners or a deep taproot. Its leaves are complex, with lower leaves deeply lobed and measuring 1 to 2 decimeters long, featuring soft-jointed hairs and prominent raised veins on the underside. The plant's involucre is ovoid to hemispheric, with phyllaries having narrow, sticky-resinous ridges and short 2 to 4 millimeter spines.
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 cymosum native to California?
Yes. Cirsium cymosum is native to California (recorded as native).
What plant family does Cirsium cymosum belong to?
Cirsium cymosum 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.