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

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

, highly variable and often shrubby, found in many areas of

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

continuing south into northern

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. It generally occurs in

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

, being most abundant in the lower elevations of the

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 primarily ...

, 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. Although the ...

—where since 1980 it has been known as a separate species ''

Quercus parvula ''Quercus parvula'', the Santa Cruz Island oak, is an evergreen red oak (Series ''Agrifoliae'', Section '' Lobatae'') found on north-facing Santa Cruz Island slopes and in the California Coast Ranges from Santa Barbara County north to Mendocino C ...

''—and the

San Gabriel Mountains The San Gabriel Mountains ( es, Sierra de San Gabriel) are a mountain range located in northern Los Angeles County, California, Los Angeles County and western San Bernardino County, California, United States. The mountain range is part of the Tr ...

. It was named for its collector,

Friedrich Adolph Wislizenus Friedrich Adolph Wislizenus (first name sometimes spelled Frederick) (21 May 1810, Königsee – 23 September 1889) was a German-born American MD, explorer and botanist. He is best known for his printed recollections from travels to Northern Mexi ...

(1810–1889).

Description

It is a large

shrub A shrub (often also called a 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 ...

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, including only woody plants with secondary growth, plants that are ...

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

foothills it seldom exceeds . The dark-green

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

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

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

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''). They contain many, usually unisexual flowers, arranged cl ...

s, the female flowers in leaf axils. The

acorn The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and '' Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and borne ...

s are long, and mature the second season (about 18 months) after flowering.

Nomenclature

Although originally published by Alphonse Pyramus de Candolle as "wislizeni", some sources, e.g., Jensen in Flora of North America, mistakenly spelled the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

"wislizenii." Correct spelling is with one "i," per ICN article 60C.2. Wislizenus' specimen was thought by de Candolle to have been collected in Chihuahua, Mexico. However, German-born American botanist

Georg Engelmann George Engelmann, also known as Georg Engelmann, (2 February 1809 – 4 February 1884) was a German-American botanist. He was instrumental in describing the flora of the west of North America, then very poorly known to Europeans; he was particul ...

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 census. Auburn is known for its California Gold Rush history and is registered as a California Historical Landmark. Au ...

. 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. More investigation is needed to resolve this taxonomic conflict. 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).Engelm., Trans. Acad. Sci. St. Louis 3:396 (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''.

Ecology

The interior live oak is a

red oak The genus Oak, ''Quercus'' contains about 500 species, some of which are listed here. The genus, as is the case with many List of the largest genera of flowering plants, large genera, is Taxonomic rank#Ranks in botany, divided into subgenus, subgen ...

(section ''Lobatae'') in the California Floristic Province (series ''Agrifoliae''). ''Q. wislizeni'' hybridizes with

California black oak ''Quercus kelloggii'', the California black oak, also known as Kellogg oak, is an oak in the red oak section (genus ''Quercus'', section ''Lobatae'', series ''Agrifoliae''), native to western North America. Although genetically separated from the ...

''(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. Intr ...

and/or

hybridization Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nu ...

with one another. A common alliant tree is

gray pine ''Pinus sabiniana'' (sometimes spelled ''P. sabineana''), with vernacular names including towani pine, foothill pine, gray pine, bull pine, and digger pine, is a pine endemic to California in the United States. Some sources discourage using the n ...

(''Pinus sabiniana''). Deer browse the tree's foliage.

Uses

Humans use the wood as a fuel source.

References

Bibliography

* * *

External links

C. Michael Hogan (2008) ''California Buckeye: Aesculus californica'', GlobalTwitcher.com, N. Stromberg ed.
{{Taxonbar, from=Q3009812 wislizeni Trees of Baja California 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