''Quercus wislizeni'', known by the common name interior live oak, is an evergreen

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

, highly variable and often shrubby, found in western North America.

Description

It is a large

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

growing to tall, although where it is common in the low-elevation

Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

foothills it seldom exceeds . The dark-green

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

—appearing grayish from a distance—are usually small, long, thick, and often spiny-toothed at higher elevations, particularly on young trees. The male

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are on

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind- pollinated ( anemophilous) but sometimes insect-pollinated (as in '' Salix''). It contains many, usually unisexual flowers, arra ...

s, the female flowers in groups of 2–4 in leaf axils. The

acorn The acorn is the nut (fruit), nut of the oaks and their close relatives (genera ''Quercus'', ''Notholithocarpus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains a seedling surrounded by two cotyledons (seedling leaves), en ...

s are long, and mature the second season (about 18 months) after flowering. Specimens can live for up to 200 years.

Taxonomy

Although originally published by Alphonse Pyramus de Candolle as "wislizeni", some sources mistakenly spelled the

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

"wislizenii". Correct spelling is with one "I", per ICN article 60C.2. Friedrich Adolph Wislizenus's specimen was thought by de Candolle to have been collected in Chihuahua, Mexico. German-born American botanist Georg Engelmann later corrected the location to the American fork of the Sacramento River near

Auburn, California Auburn is a city in and the county seat of Placer County, California, United States. Its population was 13,776 during the 2020 United States census, 2020 census. Auburn is known for its California Gold Rush history and is registered as a Califo ...

. California physician and botanist (and one of the founding fathers of the California Academy of Sciences)

Albert Kellogg Albert Kellogg (December 6, 1813 – March 31, 1887 ) was an American physician and the first resident botanist of California. He was a founding member of the California Academy of Sciences and served as its first curator of botany. Kellogg was a ...

described an oak in an 1855 publication as ''Quercus arcoglandis'' (spur acorn oak), apparently the same species as ''Q. wislizeni''. This clearly predates French-Swiss botanist de Candolle's 1864 name, and if confirmed to be this same taxon would have priority. Currently there are two recognized varieties of interior live oak: * ''Q. wislizeni'' A. DC. var. ''wislizeni'' (1864) * ''Q. wislizeni'' A. DC. var. ''frutescens'' Engelm (1878). This is an invalid taxon. Engelmann's ''Q. wislizeni'' var. ''frutescens'' description is virtually identical to de Candolle's ''Q. wislizeni,'' while Engelmann's ''Q. wislizeni'' description most closely matches Kellogg's ''Q. morehus''.

Etymology

It was named for its collector, Friedrich Adolph Wislizenus (1810–1889).

Distribution and habitat

''Q. wislizeni'' is found in many areas of California in the United States continuing south into northern

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

in Mexico. It generally occurs in

foothills Foothills or piedmont are geography, geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an highland, upland area. They are a transition zone between plains and low terrain, relief hill ...

, being most abundant in the lower elevations of the

, but also widespread in the

Pacific Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States; ; ) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Althoug ...

—where since 1980 it has been known as a separate species '' Quercus parvula''—and the

San Gabriel Mountains The San Gabriel Mountains () are a mountain range located in Los Angeles and San Bernardino counties, California, United States. The mountain range is part of the Transverse Ranges and lies between the Los Angeles Basin and the Mojave Desert ...

Ecology

The interior live oak is a red oak (section ''Lobatae'') in the California Floristic Province (series ''Agrifoliae''). ''Q. wislizeni'' hybridizes with

California black oak ''Quercus kelloggii'', the California black oak or Kellogg oak, is an oak in the red oak section (genus ''Quercus'', section ''Lobatae'', series ''Agrifoliae'') native to western North America. Description ''Quercus kelloggii'' grows from one ...

''(Q. kelloggii)'' (= ''Quercus'' × ''morehus'', Abram's oak). All California red oaks show evidence of

introgression Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introg ...

and/or hybridization with one another. A common alliant tree is gray pine (''Pinus sabiniana''). Deer browse the tree's foliage.

Uses

Humans use the wood as a fuel source. The acorns are edible.

References

Bibliography

* * *

External links

C. Michael Hogan (2008) ''California Buckeye: Aesculus californica'', GlobalTwitcher.com, N. Stromberg ed.
{{Taxonbar, from=Q3009812 wislizeni Trees of Northern America Flora of California Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of the Peninsular Ranges Natural history of the San Francisco Bay Area Natural history of the Santa Monica Mountains Natural history of the Transverse Ranges Plants described in 1864 Trees of Mediterranean climate Garden plants of North America Drought-tolerant trees Oaks of Mexico