''Quercus pungens'', commonly known as the sandpaper oak or scrub oak, is a North American species

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 ...

or sub-evergreen shrub or small 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. There is one recognised variety, '' Quercus pungens var. vaseyana'', the Vasey shin oak. Sandpaper oak hybridizes with gray oak (''

Quercus grisea ''Quercus grisea'', commonly known as the gray oak, shin oak or scrub oak, is a North American species deciduous or evergreen shrub or medium-sized tree in the white oak group. It is native to the mountains of the southwestern United States and n ...

'') in the Guadalupe Mountains of New Mexico and Texas.

Description

The sandpaper oak can be a small tree of up to high or 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 ...

that forms thickets. The

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), ...

is light brown and papery. The twigs are gray, with short velvety hairs, becoming smooth with age. The buds are dark red-brown, sparsely covered with hairs. The leathery

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

semi-evergreen Semi-deciduous or semi-evergreen is a botanical term which refers to plants that lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and sub-tropical woody spec ...

, being bright glossy green at first but turning darker with age. It is their rough texture, caused by minute persistent hair bases, that gives the tree its name of sandpaper oak. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

, which appears in spring, is reddish, the female

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 having one to three flowers and the male catkins numerous flowers. 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 shallow and covered with dense gray hairs. The acorns grow singly or in pairs and are light brown, broadly ovoid with a rounded apex.

Distribution and habitat

Sandpaper and Vasey shin oaks are abundant in the

Edwards Plateau The Edwards Plateau is a geographic region forming the crossroads of Central, South and West Texas, United States. It is named in honor of Haden Edwards. It is bounded by the Balcones Fault to the south and east; the Llano Uplift and the Lla ...

and 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 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 ...

. They also occur in the

Guadalupe Mountains The Guadalupe Mountains () are a mountain range located in West Texas and southeastern New Mexico. The range includes the highest summit in Texas, Guadalupe Peak, , and the "signature peak" of West Texas, El Capitan, both of which are located wi ...

and westward to the mountains of southeastern

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 ...

and southwestern

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 ...

, and in northern and eastern Mexico ( Chihuahua,

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 ...

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 ...

Nuevo León Nuevo León, officially the Free and Sovereign State of Nuevo León, is a Administrative divisions of Mexico, state in northeastern Mexico. The state borders the Mexican states of Tamaulipas, Coahuila, Zacatecas, and San Luis Potosí, San Luis ...

, and

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

). The preferred habitat of these oaks is on dry limestone or igneous slopes at a height of above sea level, in

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

and desert scrub

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

, usually in communities of

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 ...

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 ...

and

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 ...

Ecology

In the chaparral formations in the Guadalupe Mountains, it is one of the dominant species and is found growing alongside true mountain-mahogany (''

Cercocarpus montanus ''Cercocarpus montanus'' is a North American species of shrub or small tree in the family Rosaceae native to northern Mexico and the western United States. It is known by the common names alder-leaf mountain-mahogany, alder-leaf cercocarpus, and ...

'') and desert ceanothus (''

Ceanothus greggii ''Ceanothus pauciflorus'', known by the common name Mojave ceanothus, is a species of flowering shrub in the buckthorn family, Rhamnaceae. It is native to the Southwestern United States (Arizona, California, New Mexico, Texas, and Utah) and Mexic ...

''). Other plants associated with it include the Mohr shin oak ('' Quercus mohriana''), oneseed juniper (''

Juniperus monosperma ''Juniperus monosperma'', the New Mexico juniper or one-seed juniper, is a species of juniper native to western North America, in the United States in Arizona, New Mexico, southern Colorado, western Oklahoma (Panhandle), and western Texas, and in ...

''), cane cholla (''

Opuntia imbricata ''Cylindropuntia imbricata'', the cane cholla (walking stick cholla, tree cholla, or chainlink cactus), is a cactus found in the Southwestern United States and northern Mexico, including some cooler regions in comparison to many other cacti. It o ...

''), purplefruited pricklypear (''

Opuntia phaeacantha ''Opuntia phaeacantha'' is a species of prickly pear cactus known by the common names brown-spine prickly pear, tulip prickly pear, and desert prickly pear, which is found across the southwestern United States, lower Great Plains, and northern Me ...

''), Mexican buckeye (''

Ungnadia speciosa ''Ungnadia'' is a genus of flowering plants in the family Sapindaceae, containing one species, ''Ungnadia speciosa'', commonly known as the Mexican buckeye. It is native to northern Mexico, as well as Texas and southern New Mexico in the United ...

''), Texas persimmon (''

Diospyros texana ''Diospyros texana'' is a species of persimmon that is native to central, south and west Texas and southwest Oklahoma in the United States, and eastern Chihuahua, Coahuila, Nuevo León, and Tamaulipas in northeastern Mexico. Common names includ ...

''), hairy tridens (''

Erioneuron pilosum ''Erioneuron'' is a genus of New World plants in the grass family native to southern North America and southern South America. They are sometimes called by the common name woollygrass. These are tufty grasses with hairy spikelets.Quercus fusiformis ''Quercus fusiformis'' (also often referred to as ''Q. virginiana'' var. ''fusiformis''), commonly known as escarpment live oak, plateau live oak, plateau oak, or Texas live oak, is an evergreen or nearly evergreen tree. Its native range inc ...

'').Texas Parks and Wildlife Department. 1992. Plant communities of Texas (Series level): February 1992. Austin, TX: Texas Parks and Wildlife Department, Texas Natural Heritage Program. 38 p.

References

External links

Trees of North America
{{Taxonbar, from=Q4112482 pungens Trees of Northern America Plants described in 1854 Oaks of Mexico