Taxon Report

Boechera peirsonii Windham & Al-Shehbaz

San Bernardino rockcress

Print Report

Taxon Summary

Boechera peirsonii, commonly known as San Bernardino rockcress, is a perennial herb in the Brassicaceae that is found only in California. It occurs within Subalpine coniferous forest, growing at elevations from 2700 to 3200 meters. Boechera peirsonii is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Boechera peirsonii Windham & Al-Shehbaz
Common Name:	San Bernardino rockcress
Family:	Brassicaceae
Element Code:	PDBRA06053
USDA Plants Symbol:
Synonyms/Other Names:	Arabis breweri var. pecuniaria

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Mar-Aug	Mar-Aug
Elevation:	2700-3200 (8860-10500)
General Habitats:	Subalpine coniferous forest
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:	SB_CalBG/RSABG; USFS_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	3
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	3

Location


California Endemic: True
California Counties and Islands: Name (Code)
San Bernardino (SBD)
Quads: Name (Quad Code)
San Gorgonio Mtn. (3411617)

Threat List Data from the CNDDB


Threat List Total:	4
EOs with Threat Listed:	Total EOs	% of EOs
	2	67 %
Erosion/runoff	1	33%
Foot traffic/trampling	1	33%
Over-collecting/poaching	1	33%
Recreational use (non-ORV)	1	33%

Notes



Known from only two occurrences in the San Gorgonio Wilderness Area. Potentially threatened by foot traffic. See Rhodora 43(511):409 (1941) 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 30 October 2025].