Basic Information
Common Name: Rainbow Manzanita
Scientific Name: Arctostaphylos rainbowensis
Species Code: ARCRAI
Management Category: VF (species with limited distribution in the MSPA or needing specific vegetation characteristics requiring management)
Occurrence Map
Table of Occurrences

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].


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.

Literature Sources

[1] Parker, V. T., M. C. Vasey, and J. E. Keeley 2016. Arctostaphylos rainbowensis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on September 07, 2016

[2] CNPS, Rare Plant Program. 2016. Inventory of Rare and Endangered Plants (online edition, v8-02). California Native Plant Society, Sacramento, CA., accessed 07 September 2016.

[3] Keeley, J. E., and A. Massihi. 1994. “Arctostaphylos Rainbowensis, a New Burl-Forming Manzanita from Northern San Diego County, California.” Madroño. Los Angeles, CA.