Quercus pacifica

Quercus pacifica
Conservation status

Vulnerable  (NatureServe)
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Fagaceae
Genus: Quercus
Species: Q. pacifica
Binomial name
Quercus pacifica
Nixon & C.H. Mull.

Quercus pacifica is a species of oak known by the common names island scrub oak, Channel Island scrub oak, and Pacific oak.

Distribution

It is endemic to the Channel Islands of California, where it is known from Santa Cruz, Santa Rosa, and Santa Catalina Islands.

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.[1] It was described as a new species in 1994 from a specimen on Santa Cruz Island.[2]

Description

Quercus pacifica is a shrub or a small tree growing up to 5 metres (16 ft) in height, or occasionally taller.

The leaves are roughly oval in shape and edged with pointed teeth. The green blades are up to 4 centimeters long by 4 wide. They have shiny upper surfaces and waxy, hairy, glandular undersides.

The acorn has a cap up to 2 centimeters wide and a nut measuring 2 or 3 centimeters long.

This oak often produces a stable hybrid with Quercus lobata, that has been named Quercus × macdonaldii.[3]

Conservation

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.[1]

A new species of fungus was discovered growing in oak galls on this oak species and was named Penicillium cecidicola in 2004.[4]

References

  1. 1.0 1.1 Knapp, D. A. (2002). 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.
  2. Nixon, K. C. and C. H. Muller. (1994). New names in California oaks. Novon 4(4) 391-93.
  3. Flora of North America
  4. Seifert, K. A., et al. (2004). Penicillium cecidicola, a new species on cynipid insect galls on Quercus pacifica in the western United States. Studies in Mycology 50 517-23.

External links

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