logo Calflora, a 501c3 non-profit
Taxon  Report  
Quercus pacifica  Nixon & C. H. Mull.
Channel island scrub oak,   Island scrub oak
Quercus pacifica is a shrub that is native to California.
California Rare Plant Rank: 4.2 (limited distribution).
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
Observation Search
(299 records)
yellowone or more occurrences
within a 7.5-minute quadrangle

Bloom Period
Genus: Quercus
Family: Fagaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Toxicity: Do not eat the fruit or leaf of this plant.

Communities: Coastal Sage Scrub, Chaparral

Name Status:
Accepted by JEF + CNPS + PLANTS

Information about  Quercus pacifica from other sources
Nursery availability from CNPLX
This plant is available commercially.
Jepson eFlora


Photos on Calflora

Photos on CalPhotos

Google Images

Photos on iNaturalist

ID Tips on PlantID.net

[Wikipedia] Description, Distribution, Threats: Quercus pacifica is a shrub or a small tree growing up to 5 meters (16 feet) in height, or occasionally taller.[3] The leaves are roughly oval in shape and edged with pointed teeth. The green blades are up to 4 centimeters long by 4 cm wide. They have shiny upper surfaces and waxy, hairy, glandular undersides.[3] The acorn has a cap up to 2 cm wide and a nut measuring 2 or 3 cm long.[3] Acorn cap remaining on Q. pacifica This oak often produces a stable hybrid with Quercus lobata, that has been named Quercus macdonaldii.[3] Distribution It is endemic to the Channel Islands of California, where it is known from the islands of Santa Cruz, Santa Rosa, and Santa Catalina. The islands of Santa Cruz and Santa Rosa are part of Channel Islands National Park.[4] Though limited to three islands, it is not uncommon there, occurring in grassland, chaparral, oak woodlands, forest, and other habitat. It is the dominant oak in many areas on Catalina Island.[5] It was described as a new species in 1994 from a specimen collected on Santa Cruz Island.[6] More than a century earlier, the same plant was described as a variety of Quercus dumosa;[7] the 1994 name is nevertheless the correct name for the plant when recognized as a species because names hold priority status only within a given rank.[8] Threats This oak species is threatened by a pathogenic honey fungus (Armillaria sp.), which has been noted to infect trees already stressed by the activity of feral herbivores, including goats and pigs.[5] A new species of fungus was discovered growing in oak galls on this oak species and was named Penicillium cecidicola in 2004.[9] (contributed by Mary Ann Machi)

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2023. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 11/30/2023).