Taxon Report

Cirsium crassicaule (Greene) Jeps.

slough thistle

Print Report


Taxon Summary

Cirsium crassicaule, commonly known as slough thistle, is a annual/perennial herb in the Asteraceae that is found only in California. It occurs within Chenopod scrub, Marshes and swamps (sloughs), and Riparian scrub, growing at elevations from 3 to 100 meters. Cirsium crassicaule is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.


  Classification

Scientific Name:
Cirsium crassicaule (Greene) Jeps.
Common Name:
slough thistle
Family: Asteraceae
Element Code: PDAST2E0U0
USDA Plants Symbol: CICR
Synonyms/Other Names:

Ecology and Life History

Lifeform: annual/perennial herb
Blooming Period: May-Aug May-Aug
Elevation: 3-100 (10-330)
General Habitats: Chenopod scrub, Marshes and swamps, Riparian scrub
Microhabitat:
Microhabitat Details:

Occurrence Data from the CNDDB

Total Occurrences: 18
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 6
   Fair (C) 1
   Poor (D) 0
   None (X) 2
   Unknown (U) 9
California Endemic:  True
California Counties and Islands: Name (Code)
Kern (KRN), Kings (KNG), San Joaquin (SJQ)
Quads: Name (Quad Code)
Hacienda Ranch (3511975)?*, Lathrop (3712173), Lone Tree Well (3511976), Lost Hills NE (3511965), Lost Hills NW (3511966), Semitropic (3511955), Tupman (3511933), Vernalis (3712163), Wasco SW (3511954)

Threat List Data from the CNDDB

Threat List Total: 11
EOs with Threat Listed: Total EOs % of EOs
13 72 %
Agriculture 7 38%
Grazing 3 16%
Altered flood/tidal/hydrologic regime 2 11%
Biocides 1 5%
Dam/Inundation 1 5%
Development 1 5%
Improper burning regime 1 5%
Non-native plant impacts 1 5%
Road/trail construction/maint. 1 5%
Surface water diversion 1 5%
Waterway bank protection/maintenance 1 5%

Notes

Threatened by agriculture and non-native plants. Population sizes fluctuate widely.
Threats:
Taxonomy:
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 5 February 2025].