Taxon Report

Blennosperma nanum (Hook.) Blake var. robustum J.T. Howell

Point Reyes blennosperma

Print Report

Taxon Summary

Blennosperma nanum var. robustum, commonly known as Point Reyes blennosperma, is a annual herb in the Asteraceae that is found only in California. It occurs within Coastal prairie, and Coastal scrub, growing at elevations from 10 to 145 meters. Blennosperma nanum var. robustum is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Blennosperma nanum (Hook.) Blake var. robustum J.T. Howell
Common Name:	Point Reyes blennosperma
Family:	Asteraceae
Element Code:	PDAST1A022
USDA Plants Symbol:	BLNAR
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Feb-Apr	Feb-Apr
Elevation:	10-145 (35-475)
General Habitats:	Coastal prairie, Coastal scrub
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G4T2
State Rank:	S2
State List:	CR
Fed List:	None
Other Status:	SB_CalBG/RSABG
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	13
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	8
Fair (C)	2
Poor (D)	0
None (X)	0
Unknown (U)	2

Location


California Endemic: True
California Counties and Islands: Name (Code)
Marin (MRN), Mendocino (MEN)
Quads: Name (Quad Code)
Drakes Bay (3812218), Fort Bragg (3912347), Tomales (3812228)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	12	92 %
Grazing	6	46%
Foot traffic/trampling	5	38%
Non-native plant impacts	4	30%
Other	4	30%
Road/trail construction/maint.	2	15%
Recreational use (non-ORV)	1	7%
Erosion/runoff	1	7%
Mining	1	7%

Notes



Threatened by competition and foot traffic. Possibly threatened by grazing, non-native plants, and trampling. Potentially threatened by trail construction. Plants found near Ft. Bragg in 1988 appear closest to this taxon. Some Pt. Reyes populations intermediate to var. nanum. See Leaflets of Western Botany 5:105-108 (1948) for original description.
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 3 November 2025].