San Diego Management & Monitoring Program


Rainbow manzanita
Arctostaphylos rainbowensis


Kingdom Phylum Subphylum Class Order Suborder Family

Current distribution rangewide

Peninsular Ranges of San Diego and Riverside County [1].


Known Populations in San Diego County

Five occurrences on Conserved Lands in MUs 8 (BLM, Margarita Peak, Rock Mountain Preserve, Santa Margarita River Park) and 9 (Cleveland National Forest).


List status

None [2].


Habitat affinities

Granitic outcrops and chaparral [1]. Elevation range is 150-800 meters.


Taxonomy and genetics

Ericaceae family [3]. Previously called A. peninsularis ssp. peninsularis or considered a hybrid of A. glandulosa and A. glauca. Possibly hybridization with A. glandulosa at the edge of the A. rainbowensis range.


Life history demography

Perennial evergreen shrub [2]. Burl-forming and vigorous at resprouting [3].


Seasonal phenology

Bloom period is December-March [2].


Pollination seed dispersal

Produces large amount of fruits and readily establishes seedlings on sites disturbed by bulldozers or wildfires [3].


Threats

Development and agricultural conversion [2].


Special considerations:

Flowers and fruits are often heavily infested with boring insects on the eastern edge of its range [3]. A. rainbowensis is the only Arctostaphylos species throughout most of its range.


Rainbow manzanita sources