Quercus pacifica
Encyclopedia
Quercus pacifica is a species of oak
known by the common name island scrub oak. It is endemic to the Channel Islands of California
, where it is known from Santa Cruz
, Santa Rosa
, and Santa Catalina Islands
. While 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.
This is a shrub
or a small tree
growing up to five meters 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 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.
This oak often produces a stable hybrid with Quercus lobata that has been named Quercus × macdonaldii.
A new species of fungus was discovered growing in oak galls
on this oak species and was named Penicillium cecidicola in 2004.
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
known by the common name island scrub oak. It is endemic to the Channel Islands of California
Channel Islands of California
The Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel in the United States of America...
, where it is known from Santa Cruz
Santa Cruz Island
Santa Cruz Island was the largest privately owned island off the continental United States, but is currently part-owned by the National Park service . The island, located off the coast of California, is long and from wide...
, Santa Rosa
Santa Rosa Island
There are at least two islands named Santa Rosa Island:*Santa Rosa Island, California, one of the Channel Islands*Santa Rosa Island, Florida**Battle of Santa Rosa Island, a battle of the American Civil War...
, and Santa Catalina Islands
Santa Catalina Island
Santa Catalina Island, or Catalina Island, may refer to:*Santa Catalina Island, California*Catalina Island, Dominican Republic*Archipelago of San Andrés, Providencia and Santa Catalina, one of the departments of Colombia, consisting of two island groups*Owariki or Owa Riki , an island in the...
. While limited to three islands, it is not uncommon there, occurring in grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
, oak woodlands
California oak woodland
California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico...
, forest, and other habitat. It is the dominant oak in many areas on Catalina Island.
This is a shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
or a small tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
growing up to five meters 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
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
has a cap up to 2 centimeters wide and a nut measuring 2 or 3 centimeters long.
This oak species is threatened by a pathogenic honey fungus
Honey fungus
Honey fungus, or Armillaria or оpenky , is a genus of parasitic fungi that live on trees and woody shrubs. It includes about 10 species formerly lumped together as A. mellea. Armillarias are long lived and form some of the largest living organisms in the world...
(Armillaria sp.), which has been noted to infect trees already stressed by the activity of feral herbivores, including goats
Feral goat
The feral goat is the domestic goat when it has become established in the wild. Feral goats occur in Australia, New Zealand, Ireland, Great Britain, Hawaii, the Galapagos and in many other parts of the world...
and pigs.
This oak often produces a stable hybrid with Quercus lobata that has been named Quercus × macdonaldii.
A new species of fungus was discovered growing in oak galls
Oak apple
Oak apple is the common name for a large, round, vaguely apple-like gall commonly found on many species of oak. Oak apples range in size from 2-5cm. Oak apples are caused by chemicals injected by the larva of certain kinds of gall wasp in the family Cynipidae. The adult female wasp lays single...
on this oak species and was named Penicillium cecidicola in 2004.