Cirsium occidentale(Nutt.) Jeps.

Cobwebby Thistle

WFO wfo-0000074921 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Cirsium occidentale, photographed by Amthinkia
fig. a Amthinkia, CC0 1.0 / 2022-04-17 / obs. 189474087
Cirsium occidentale, photographed by Wendy St. John
fig. b Wendy St. John, CC BY-SA 4.0 / obs. 204065577
Cirsium occidentale, photographed by Karen Offereins
fig. c Karen Offereins, CC BY 4.0 / obs. 189173166
Cirsium occidentale, photographed by paulexcoff
fig. d paulexcoff, CC BY-SA 4.0 / obs. 194832825
Cirsium occidentale, photographed by Wendy St. John
fig. e Wendy St. John, CC BY-SA 4.0 / obs. 204065803
Cirsium occidentale, photographed by Arvel Hernandez
fig. f Arvel Hernandez, CC BY 4.0 / obs. 188685181
Cirsium occidentale, photographed by Dutza K.
fig. g Dutza K., CC BY 4.0 / obs. 197717978
Cirsium occidentale, photographed by rappman
fig. h rappman, CC BY 4.0 / obs. 202065715

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Flowering n = 3,160 observations

Peak flowering in May, from 3,160 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 22 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Carduus bernardinus Greene
  • Carduus californicus Greene
  • Carduus californicus var. californicus
  • Carduus candidissimus Greene
  • Carduus venustus Greene
  • Cirsium bernardinum Petr.
  • Cirsium bernardinum Davidson & Moxley
  • Cirsium californicum A.Gray
  • Cirsium californicum subsp. californicum
  • Cirsium californicum var. bernardinum Petr.
  • Cirsium californicum var. californicum
  • Cirsium candidissimum Davidson & Moxley
  • Cirsium coulteri Jeps.
  • Cirsium occidentale subsp. candidissimum Petr.
  • Cirsium occidentale subsp. candissimum
  • Cirsium occidentale subsp. eu-occidentale Petr.
  • Cirsium occidentale subsp. venustum Petr.
  • Cirsium pastoris J.T.Howell
  • Cirsium proteanum J.T.Howell
  • Cnicus californicus A.Gray
  • Cnicus lilacinus Greene
  • Cnicus occidentalis (Nutt.) A.Gray

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.

We publish what we can source and we say so when we cannot. This page has no care advice, no toxicity claim and no native range, because we do not yet have those from a source we can cite.