''Quercus grisea'', commonly known as the gray oak, shin oak or scrub oak, is a North American species

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

shrub or medium-sized tree in the

white oak ''Quercus'' subgenus ''Quercus'' is one of the two subgenera into which the genus ''Quercus'' was divided in a 2017 classification (the other being subgenus ''Cerris''). It contains about 190 species divided among five sections. It may be calle ...

group. It is native to the mountains of the southwestern United States and northern Mexico. It hybridises with four other oak species where the ranges overlap, the

Arizona white oak ''Quercus arizonica'', the Arizona white oak, is a North American tree species in the beech family. It is found in Arizona, New Mexico, western Texas, Sonora, Chihuahua, Coahuila, Sinaloa, and Durango. Description The Arizona white oak is o ...

(''Q. arizonica''), the

Gambel oak ''Quercus gambelii'', with the common name Gambel oak, is a deciduous small tree or large shrub that is widespread in the foothills and lower mountains of western North America. It is also regionally called scrub oak, oak brush, and white oak. T ...

(''Q. gambelii''), the Mohr oak (''Q. mohriana'') and the sandpaper oak (''Q. pungens'').

Description

''Quercus grisea'' may grow as a multi-stemmed

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 ...

in drier situations but where the rainfall is sufficient, it grows into a medium size

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 ...

of up to about with an irregular

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, parti ...

of twisted branches. The trunk is up to in diameter with light gray

bark Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...

which is fissured and cracked into small plates. The twigs are stout and a light reddish-brown, covered with grayish down. The

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, ...

are alternate, leathery, long ovate, entire or with a few coarse teeth. They are grayish-green above and felted beneath and may fall in times of winter drought. The male

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 are yellowish-green and the female flowers are in small spikes growing in the leaf axils and appear in spring at the same time as the new leaves. 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 ...

cups are scaly, covered with fine hairs, and half as long as the acorns which grow singly or in pairs and are light brown.

Distribution and habitat

The gray oak grows in the mountains of the southwestern United States (western

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

, and the Oklahoma Panhandle) and northern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

(

Sonora Sonora (), officially Estado Libre y Soberano de Sonora (), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is divided into Municipalities of Sonora, 72 ...

Sinaloa Sinaloa (), officially the (), is one of the 31 states which, along with Mexico City, compose the Federal Entities of Mexico. It is divided into 18 municipalities, and its capital city is Culiacán Rosales. It is located in northwest Mexic ...

, Chihuahua,

Durango Durango, officially the Free and Sovereign State of Durango, is one of the 31 states which make up the Political divisions of Mexico, 32 Federal Entities of Mexico, situated in the northwest portion of the country. With a population of 1,832,650 ...

Coahuila Coahuila, formally Coahuila de Zaragoza, officially the Free and Sovereign State of Coahuila de Zaragoza, is one of the 31 states of Mexico. The largest city and State Capital is the city of Saltillo; the second largest is Torreón and the thi ...

San Luis Potosí San Luis Potosí, officially the Free and Sovereign State of San Luis Potosí, is one of the 32 states which compose the Federal Entities of Mexico. It is divided in 59 municipalities and is named after its capital city, San Luis Potosí. It ...

Zacatecas Zacatecas, officially the Free and Sovereign State of Zacatecas, is one of the Political divisions of Mexico, 31 states of Mexico. It is divided into Municipalities of Zacatecas, 58 municipalities and its capital city is Zacatecas City, Zacatec ...

, Hidalgo). Through generally scarce, it is common in the

Trans-Pecos The Trans-Pecos, as originally defined in 1887 by the Texas geologist Robert T. Hill, is the distinct portion of Texas that lies west of the Pecos River. The term is considered synonymous with Far West Texas, a subdivision of West Texas. The Tran ...

region of Texas.SEINet, Southwestern Biodiversity, Arizona chapter
/ref> The gray oak occurs from above sea level, growing in valleys and on ridges, on rocky slopes and on the banks of streams. It flourishes in semi-arid conditions characterized by mild winters, dry springs and hot summers. It can spread asexually through the sprouting of root suckers and may form thickets. It grows in association with other

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 ...

s, species of

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

Mexican pinyon ''Pinus cembroides'', also known as pinyon pine, Mexican pinyon, Mexican nut pine, and Mexican stone pine, is a pine in the pinyon pine group. It is a small pine growing to about with a trunk diameter of up to . It is native to western North Am ...

(''Pinus cembroides''),

pinyon pine The pinyon or piñon pine group grows in southwestern North America, especially in New Mexico, Colorado, Arizona, and Utah, with the single-leaf pinyon pine just reaching into southern Idaho. The trees yield edible Pine nut, nuts, which are a sta ...

(''Pinus edulis''), fendlerbush (''Fendlera rupicola''), bushy sage (''Salvia lycioides''), Texas madrone (''Arbutus xalapensis ''), Fremont barberry (''Berberis fremontii''), Louisiana sagewort (''Artemisia ludoviciana'') and soaptree yucca (''Yucca elata'').

References

External links

Tropicos.org: Photo of herbarium specimen collected in 1846
{{Taxonbar, from=Q4112218 grisea Trees of Northern America Plants described in 1854 Flora of the Sierra Madre Occidental Oaks of Mexico