Taxon Report

Chorizanthe cuspidata Wats. var. villosa (Eastw.) Munz

woolly-headed spineflower

Print Report

Taxon Summary

Chorizanthe cuspidata var. villosa, commonly known as woolly-headed spineflower, is a annual herb in the Polygonaceae that is found only in California. It occurs within Coastal dunes, Coastal prairie, and Coastal scrub, growing at elevations from 3 to 60 meters. Chorizanthe cuspidata var. villosa is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Chorizanthe cuspidata Wats. var. villosa (Eastw.) Munz
Common Name:	woolly-headed spineflower
Family:	Polygonaceae
Element Code:	PDPGN04082
USDA Plants Symbol:	CHCUV
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: May-Jul(Aug)	May-Jul(Aug)
Elevation:	3-60 (10-195)
General Habitats:	Coastal dunes, Coastal prairie, Coastal scrub
Microhabitat:	Sandy
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2T2
State Rank:	S2
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	17
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	7
Fair (C)	1
Poor (D)	0
None (X)	0
Unknown (U)	9

Location


California Endemic: True
California Counties and Islands: Name (Code)
Marin (MRN), Sonoma (SON)
Quads: Name (Quad Code)
Bodega Head (3812331), Drakes Bay (3812218), Plantation (3812353), Tomales (3812228), Valley Ford (3812238)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	9	53 %
Non-native plant impacts	7	41%
Agriculture	2	11%
Development	1	5%
Disking	1	5%
Foot traffic/trampling	1	5%
Grazing	1	5%
Mining	1	5%
Wood cutting or brush clearing	1	5%

Notes



Threatened by agriculture, development and non-native plants. See C. cuspidata in The Jepson Manual. See Bulletin of the Torrey Botanical Club 30:485 (1903) for original description, and Phytologia 66(2):127-130 (1989) for taxonomic treatment.
Threats:

Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 7 December 2025].