Taxon Report

Petalonyx thurberi Gray ssp. gilmanii (Munz) Davis & Thompson

Death Valley sandpaper-plant

Print Report

Taxon Summary

Petalonyx thurberi ssp. gilmanii, commonly known as Death Valley sandpaper-plant, is a perennial evergreen shrub in the Loasaceae that is found only in California. It occurs within Desert dunes, and Mojavean desert scrub, growing at elevations from 260 to 1445 meters. Petalonyx thurberi ssp. gilmanii is ranked 1B.3, Plants Rare, Threatened or Endangered in California and Elsewhere; Not very threatened in California.

Classification


Scientific Name:	Petalonyx thurberi Gray ssp. gilmanii (Munz) Davis & Thompson
Common Name:	Death Valley sandpaper-plant
Family:	Loasaceae
Element Code:	PDLOA04041
USDA Plants Symbol:	PETHG
Synonyms/Other Names:	Petalonyx gilmanii

Ecology and Life History


Lifeform:	perennial evergreen shrub
Blooming Period: May-Sep	May-Sep
Elevation:	260-1445 (855-4740)
General Habitats:	Desert dunes, Mojavean desert scrub
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.3
Global Rank:	G5T2
State Rank:	S2
State List:	None
Fed List:	None
Other Status:	BLM_S; SB_CalBG/RSABG
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	18
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	5
Fair (C)	4
Poor (D)	0
None (X)	0
Unknown (U)	8

Location


California Endemic: True
California Counties and Islands: Name (Code)
Inyo (INY), San Bernardino (SBD)
Quads: Name (Quad Code)
Cottonwood Canyon (3611753), Darwin (3611735), East of Sand Flat (3611763), Fall Canyon (3611772), Ibex Spring (3511674), Maturango Peak NE (3611723), Maturango Peak SE (3611713), Nova Canyon (3611733), Old Ibex Pass (3511664), Panamint Springs (3611734), Ryan (3611636), Stovepipe Wells (3611752), The Dunes (3611744), Ubehebe Crater (3711714)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	10	56 %
Road/trail construction/maint.	6	33%
Mining	4	22%
ORV activity	2	11%
Other	1	5%
Recreational use (non-ORV)	1	5%
Non-native plant impacts	1	5%
Erosion/runoff	1	5%
Foot traffic/trampling	1	5%

Notes



Distinctiveness from ssp. thurberi needs study.
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 5 February 2025].