Taxon Report

Frangula purshiana Cooper ssp. ultramafica J.O. Sawyer & S.W. Edwards

Caribou coffeeberry

Print Report

Taxon Summary

Frangula purshiana ssp. ultramafica, commonly known as Caribou coffeeberry, is a perennial deciduous shrub in the Rhamnaceae that is found only in California. It occurs within Chaparral, Lower montane coniferous forest, Meadows and seeps, and Upper montane coniferous forest, growing at elevations from 825 to 1930 meters. Frangula purshiana ssp. ultramafica is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Frangula purshiana Cooper ssp. ultramafica J.O. Sawyer & S.W. Edwards
Common Name:	Caribou coffeeberry
Family:	Rhamnaceae
Element Code:	PDRHA0H061
USDA Plants Symbol:	FRPUU
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial deciduous shrub
Blooming Period: May-Jul	May-Jul
Elevation:	825-1930 (2705-6330)
General Habitats:	Chaparral, Lower montane coniferous forest, Meadows and seeps, Upper montane coniferous forest
Microhabitat:	Serpentine
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G5T2T3
State Rank:	S2S3
State List:	None
Fed List:	None
Other Status:	SB_UCSC; USFS_S
CRPR Changes:	added to 1B.2 on 2008-02-14

Occurrence Data from the CNDDB


Total Occurrences:	36
Element Occurrence Ranks:
Excellent (A)	3
Good (B)	4
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	29

Location


California Endemic: True
California Counties and Islands: Name (Code)
Butte (BUT), Plumas (PLU), Sierra (SIE)
Quads: Name (Quad Code)
Belden (4012113), Bucks Lake (3912182), Caribou (4012112), Haskins Valley (3912172), La Porte (3912068), Meadow Valley (3912181), Onion Valley (3912078), Paradise East (3912175), Quincy (3912088), Soapstone Hill (3912173), Spring Garden (3912087), Twain (4012111)

Threat List Data from the CNDDB


Threat List Total:	11
EOs with Threat Listed:	Total EOs	% of EOs
	19	53 %
Road/trail construction/maint.	12	33%
Logging	7	19%
Improper burning regime	5	13%
Other	4	11%
Mining	2	5%
Non-native plant impacts	2	5%
Altered flood/tidal/hydrologic regime	2	5%
Erosion/runoff	2	5%
Foot traffic/trampling	1	2%
Development	1	2%
ORV activity	1	2%

Notes



Threatened by road maintenance, mining, and vehicles. Not in TJM (1993). See Madroño 54(2): 172-174 (2007) for original description.
Threats:

Taxonomy:

Selected References

CRPR List Addition on 2008-02-14

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].