Taxon Report

Mentzelia tricuspis A. Gray

spiny-hair blazing star

Print Report

Taxon Summary

Mentzelia tricuspis, commonly known as spiny-hair blazing star, is a annual herb in the Loasaceae that is found in California and elsewhere. It occurs within Mojavean desert scrub, growing at elevations from 150 to 1280 meters. Mentzelia tricuspis is ranked 2B.1, Plants Rare, Threatened, or Endangered in California, But More Common Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Mentzelia tricuspis A. Gray
Common Name:	spiny-hair blazing star
Family:	Loasaceae
Element Code:	PDLOA031T0
USDA Plants Symbol:	METR2
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Mar-May	Mar-May
Elevation:	150-1280 (490-4200)
General Habitats:	Mojavean desert scrub
Microhabitat:	Gravelly, Sandy, Slopes, Washes
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	2B.1
Global Rank:	G4
State Rank:	S2
State List:	None
Fed List:	None
Other Status:
CRPR Changes:	changed from 2.1 to 2B.1 on 2013-06-12 added to 2.1 on 2010-10-28

Occurrence Data from the CNDDB


Total Occurrences:	16
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	16

Location


California Endemic: False
California Counties and Islands: Name (Code)
Imperial (IMP), Inyo (INY), Riverside (RIV), San Bernardino (SBD), San Diego (SDG)
Quads: Name (Quad Code)
Bannock (3411487), Barstow (3411781), Beaumont (3311688), Blackwater Mine (3511577), Cottonwood Spring (3311567), Desert Hot Springs (3311685), East of Homer Mtn. (3511417), Flattop Mtn. (3411477), Havasu Lake (3411444), In-ko-pah Gorge (3211661), Monumental Pass (3411466), Mt. Manchester (3511416), Needles (3411475), Needles Nw (3411486), Needles SW (3411476), Topock (3411464), White Water (3311686)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	%

Notes



Single record from IMP Co. is likely M. hirsutissima. Occurrences from RIV Co. need quads and verification. Need quads for INY Co. Possibly threatened by renewable energy development.
Threats:

Taxonomy:

Selected References

CRPR List Addition on 2010-10-28

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 19 November 2025].