Taxon Report

Boechera ultraalsa Windham & Al-Shehbaz

Snow Mountain rockcress

Print Report

Taxon Summary

Boechera ultraalsa, commonly known as Snow Mountain rockcress, is a perennial herb in the Brassicaceae that is found only in California. It occurs within Upper montane coniferous forest, growing at elevations from 1800 to 1800 meters. Boechera ultraalsa is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Boechera ultraalsa Windham & Al-Shehbaz
Common Name:	Snow Mountain rockcress
Family:	Brassicaceae
Element Code:	PDBRA40140
USDA Plants Symbol:
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Jun-Jul	Jun-Jul
Elevation:	1800-1800 (5905-5905)
General Habitats:	Upper montane coniferous forest
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:
CRPR Changes:	added to 1B.1 on 2011-06-01

Occurrence Data from the CNDDB


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

Location


California Endemic: True
California Counties and Islands: Name (Code)
Lake (LAK)
Quads: Name (Quad Code)
Potato Hill (3912237)

Threat List Data from the CNDDB


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

Notes



Known from only one occurrence on Snow Mtn.
Threats:

Taxonomy:
Previously identified as Arabis (Boechera) platysperma.

Selected References

Proposed New Add to Rank 1B.1, G1 / S1

Harvard Papers in Botany 11(1):61-88 (2006)

Boechera ultraalsa profile for potential Species of Conservation Concern evaluation (2018)

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].