Cirsium occidentale var. californicum

California thistle

Family:Asteraceae

Rarity

CNPS-EB: A2

9 current natural populations

Criteria:

Narrow Range in ALA & CCA
Small Populations

Observations

Key

Ecology

Flowers April - July

Habitats:

Forest
Woodland

All Cirsium

References

Populations

Key

Location	Pop ID	Last Recorded	Notes
Calaveras Reservoir, SFWD	8	2009-06-16
Maguire Peaks, Sunol Regional Wilderness	7	2009-06-05
Mt. Diablo State Park - East side	9	2014-04-12
Mt. Diablo State Park - North side	5	2005-08-08
Mt. Diablo State Park - North side	11	2021-04-16
Mt. Diablo State Park - South side	10	2021-04-23
Mt. Diablo State Park - Summit and Upper area - 2500 ft and abo	4	2014-04-25
Mt. Diablo State Park - Summit and Upper area - 2500 ft and abo	12	2023-05-01
San Francisco Water District land, Sunol	6	2009-06-01
Mt. Diablo State Park - Summit and Upper area - 2500 ft and abo	1	1935-05-16	Historic
Mt. Diablo State Park - Summit and Upper area - 2500 ft and abo	2	1934-04-21	Historic
Mt. Diablo State Park - Summit and Upper area - 2500 ft and abo	3	1997-05-27	Historic

The list of populations shows the distinct populations identified by the CNPS-EB Rare and Unusual Plants Committee. The locations in this list are very general. More specific location details can be obtained from the links in the Observations section (for some of these links, a login is required).

Font

Populations in bold type have precise coordinates available for field volunteers and researchers.

Populations in normal type are only known from a description of the location; no precise coordinates are available.

Background

Populations with a white background have been observed in the last 25 years.

Populations with a blue background have not been observed for at least 25 years.

Populations with an orange background have an uncertain location or identification, or are planted.

Columns

Pop ID is a label that identifies the population. Many locations have more than one population of a species, and the population ID is used to distinguish them.