Quercus pacifica

Quercus pacifica is a shrub or a small tree growing up to {{convert|5|m|ft|sp=us|abbr=off}} in height, or occasionally taller.

The leaves are roughly oval in shape and edged with pointed teeth. The green blades are up to {{Convert|4|cm|abbr=off|sp=us|frac=2}} long by 4 cm wide. They have shiny upper surfaces and waxy, hairy, glandular undersides.

The acorn has a cap up to {{Convert|2|cm|abbr=on|frac=8}} wide and a nut measuring {{Convert|2 or 3|cm|abbr=on|frac=4}} long.

File:Quercus pacifica 3.jpg

This oak often produces a stable hybrid with Quercus lobata, that has been named Quercus × macdonaldii.{{eFloras|1|233501070|Quercus pacifica |family=Fagaceae |first=Kevin C. |last=Nixon}}

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.{{Calflora|Quercus pacifica}}

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.Knapp, D. A. (2002). [http://www.fs.fed.us/psw/publications/documents/psw_gtr184/073_Knapp.pdf The Status of Island Scrub Oak (Quercus pacifica) on Catalina Island, California.] In: Standiford, R. B., et al. Proceedings of the Fifth Symposium on Oak Woodlands: Oaks in California's Challenging Landscape. Gen. Tech. Rep. USDA Forest Service. It was described as a new species in 1994 from a specimen collected on Santa Cruz Island.{{cite journal |last1=Nixon |first1=K. C. |last2=Muller |first2=C. H. |date=1994 |title=New names in California oaks |url=https://biodiversitylibrary.org/page/639803 |journal=Novon |volume=4 |issue=4 |pages=391–392 |doi=10.2307/3391450 |jstor=3391450|bibcode=1994Novon...4..391N }} More than a century earlier, the same plant was described as a variety of Quercus dumosa;Greene, Edward Lee. 1889. Illustrations of West American Oaks 36, 61, plate 28 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.[http://iapt-taxon.org/nomen/main.php?page=art11 International Code of Nomenclature for algae, fungi, and plants (Melbourne Code)] section 11.2

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.

A new species of fungus was discovered growing in oak galls on this oak species and was named Penicillium cecidicola in 2004.Seifert, K. A., et al. (2004). [http://www.cbs.knaw.nl/publications/1050/047-Penicillium%20cecidicola,%20a%20new%20species%20on%20cynipid%20insect%20galls%20on%20Quercus%20pacifica%20in%20the%20western%20United%20States.pdf Penicillium cecidicola, a new species on cynipid insect galls on Quercus pacifica in the western United States.] {{Webarchive|url=https://web.archive.org/web/20160304051954/http://www.cbs.knaw.nl/publications/1050/047-Penicillium%20cecidicola,%20a%20new%20species%20on%20cynipid%20insect%20galls%20on%20Quercus%20pacifica%20in%20the%20western%20United%20States.pdf |date=2016-03-04 }} Studies in Mycology 50 517-23.

{{Reflist}}

• {{Jepson eFlora|80203 |link=1}}
• [http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Quercus+pacifica The Nature Conservancy]{{Dead link|date=March 2025 |bot=InternetArchiveBot |fix-attempted=yes }}
• {{CalPhotos|Quercus|pacifica}}

{{commons category|position=left}}

{{Taxonbar|from=Q7271346}}

pacifica

Category:Endemic flora of California

Category:Natural history of the California chaparral and woodlands

Category:Natural history of the Channel Islands of California

Category:Plants described in 1994

Category:Channel Islands National Park