Taxon Report

Clarkia gracilis (Piper) Nels. & Macbr. ssp. albicaulis (Jeps.) Lewis & Lewis

white-stemmed clarkia

Print Report

Taxon Summary

Clarkia gracilis ssp. albicaulis, commonly known as white-stemmed clarkia, is a annual herb in the Onagraceae that is found only in California. It occurs within Chaparral, and Cismontane woodland, growing at elevations from 245 to 1085 meters. Clarkia gracilis ssp. albicaulis is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Clarkia gracilis (Piper) Nels. & Macbr. ssp. albicaulis (Jeps.) Lewis & Lewis
Common Name:	white-stemmed clarkia
Family:	Onagraceae
Element Code:	PDONA050J1
USDA Plants Symbol:	CLGRA
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: (Apr)May-Jul	(Apr)May-Jul
Elevation:	245-1085 (805-3560)
General Habitats:	Chaparral, Cismontane woodland
Microhabitat:	Serpentine (sometimes)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G5T3
State Rank:	S3
State List:	None
Fed List:	None
Other Status:	BLM_S; SB_UCBG; USFS_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	32
Element Occurrence Ranks:
Excellent (A)	4
Good (B)	10
Fair (C)	2
Poor (D)	0
None (X)	0
Unknown (U)	16

Location


California Endemic: True
California Counties and Islands: Name (Code)
Butte (BUT), Tehama (TEH)
Quads: Name (Quad Code)
Acorn Hollow (4012118), Barkley Mtn. (4012126), Berry Creek (3912164), Cherokee (3912165), Cohasset (3912186), Devils Parade Ground (4012116), Forbestown (3912153), Paradise East (3912175), Paradise West (3912176), Pulga (3912174), Richardson Springs (3912177)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	16	50 %
Road/trail construction/maint.	13	40%
Non-native plant impacts	4	12%
Erosion/runoff	2	6%
Logging	1	3%
Mining	1	3%
Recreational use (non-ORV)	1	3%
Vandalism/dumping/litter	1	3%
Biocides	1	3%

Notes



Threatened by urbanization and non-native plants. Possibly threatened by erosion and road maintenance. See University of California Publications in Botany 2:239 (1907) for original description and 20:241-392 (1955) for taxonomic treatment.
Threats:

Taxonomy:

Selected References

USFS Potential Species of Conservation Concern Profile

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 27 January 2025].