Species Details

Arctostaphylos osoensis

Oso manzanita

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Species Description:

Arctostaphylos osoensis, commonly known as Oso manzanita, is a perennial evergreen shrub in the Ericaceae that is found only in California. It occurs within Chaparral, and Cismontane woodland, growing at elevations from 95 to 500 meters. Arctostaphylos osoensis is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification

Scientific Name: Arctostaphylos osoensis Wells
Common Name: Oso manzanita
Family:	Ericaceae
Element Code:	PDERI042S0
USDA Plants Symbol:	AROS
Synonyms/Other Names:
Name Status:	JEP, FNA, POWO, IPNI, Tropicos

Conservation Status

CA Rare Plant Rank:	1B.2
Fed List:	None
State List:	None
Global Rank:	G1
State Rank:	S1
Other Status:	SB_UCSC
CRPR Changes:
Add Date:	1994-01-01
Date Edited:	2022-12-06

Ecology and Life History

Lifeform: perennial evergreen shrub

Blooming Period: Feb-Mar

Elevation:
95 - 500 meters
310 - 1640 feet

General Habitats:

Chaparral
Cismontane woodland

Microhabitat Details: dacite porphyry buttes

Microhabitat:

Notes

Notes: Known only from two occurrences in the mountains north of Los Osos Valley. Threatened by urbanization. See Four Seasons 9(2):45 (1992) for original description.
Threats:
Taxonomy:

Threat List Data from the CNDDB

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

Occurrence Data from the CNDDB

Element Occurrence Ranks:
Total Occurrences:					11
A	B	C	D	X	U
1	0	0	0	0	10

Occurrence Status:
Historical >20 Years	3
Recent <=20 Years	8

Presence:
Presumed Extant	11
Possibly Extirpated	0
Presumed Extirpated	0

Location

California Endemic:

California Island:

States: Name (Code)
California (CA)

California Counties and Islands: Name (Code)
San Luis Obispo (SLO)

Quads: Name (Quad Code)
Morro Bay South (3512037), San Luis Obispo (3512036)

Notes:

Definitions of codes following a county and/or quad:
*		Presumed extirpated
(?)		Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.

Regional Map

Map

Presumed Extant

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CNPS Rare Plant Inventory