Taxon Report

Arctostaphylos confertiflora Eastw.

Santa Rosa Island manzanita

Print Report

Taxon Summary

Arctostaphylos confertiflora, commonly known as Santa Rosa Island manzanita, is a perennial evergreen shrub in the Ericaceae that is found only in California. It occurs within Broadleafed upland forest, Chaparral, and Closed-cone coniferous forest, growing at elevations from 40 to 500 meters. Arctostaphylos confertiflora is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Arctostaphylos confertiflora Eastw.
Common Name:	Santa Rosa Island manzanita
Family:	Ericaceae
Element Code:	PDERI040A0
USDA Plants Symbol:	ARCO13
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial evergreen shrub
Blooming Period: Feb-Apr	Feb-Apr
Elevation:	40-500 (130-1640)
General Habitats:	Broadleafed upland forest, Chaparral, Closed-cone coniferous forest
Microhabitat:	Rocky, Sandstone
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2
State Rank:	S2
State List:	None
Fed List:	FE
Other Status:	SB_CalBG/RSABG; SB_SBBG; SB_USDA
CRPR Changes:

Occurrence Data from the CNDDB


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

Location


California Endemic: True
California Counties and Islands: Name (Code)
Santa Barbara (SBA)
Quads: Name (Quad Code)
Santa Rosa Island East (3311988), Santa Rosa Island North (3312081), Santa Rosa Island South (3312071)

Threat List Data from the CNDDB


Threat List Total:	1
EOs with Threat Listed:	Total EOs	% of EOs
	4	100 %
Erosion/runoff	4	100%

Notes



Fewer than 400 plants were estimated to occur as of 1996. See Leaflets of Western Botany 1:122 (1934) for original description.
Threats:
Threatened by cattle grazing and feral herbivores.
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 24 October 2025].