Taxon Report

Cirsium ciliolatum (Henders.) J.T. Howell

Ashland thistle

Print Report

Taxon Summary

Cirsium ciliolatum, commonly known as Ashland thistle, is a perennial herb in the Asteraceae that is found in California and elsewhere. It occurs within Cismontane woodland, and Valley and foothill grassland, growing at elevations from 800 to 1400 meters. Cirsium ciliolatum is ranked 2B.1, Plants Rare, Threatened, or Endangered in California, But More Common Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Cirsium ciliolatum (Henders.) J.T. Howell
Common Name:	Ashland thistle
Family:	Asteraceae
Element Code:	PDAST2E0P0
USDA Plants Symbol:	CICI
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Jun-Aug	Jun-Aug
Elevation:	800-1400 (2625-4595)
General Habitats:	Cismontane woodland, Valley and foothill grassland
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	2B.1
Global Rank:	G3
State Rank:	S1
State List:	CE
Fed List:	None
Other Status:	BLM_S
CRPR Changes:	changed from 2.1 to 2B.1 on 2006-07-14

Occurrence Data from the CNDDB


Total Occurrences:	5
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	1
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	4

Location


California Endemic: False
California Counties and Islands: Name (Code)
Siskiyou (SIS)
Quads: Name (Quad Code)
Bogus Mountain (4112274), Dewey Gulch (4112273)

Threat List Data from the CNDDB


Threat List Total:	4
EOs with Threat Listed:	Total EOs	% of EOs
	2	40 %
Road/trail construction/maint.	2	40%
Biocides	1	20%
Non-native plant impacts	1	20%
Other	1	20%

Notes



Known in CA from fewer than ten occurrences. Threatened by agriculture and road maintenance. Possibly threatened by grazing. On review list in OR. See Bulletin of the Torrey Botanical Club 27:348 (1900) for original description.
Threats:

Taxonomy:

Selected References

CRPR List Change on 2006-07-14

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 24 October 2025].