Quercus turbinella

Quercus turbinella is a shrub growing 2–5 metres (6+1⁄2–16+1⁄2 feet) in height but sometimes becoming treelike and exceeding 6 m (20 ft). The branches are gray or brown, the twigs often coated in short woolly fibers when young and becoming scaly with age. The thick, leathery evergreen leaves are up to 3 centimetres (1+1⁄4 inches) long by 2 cm (3⁄4 in) wide and are edged with large, spine-tipped teeth. They are gray-green to yellowish in color and waxy in texture on the upper surfaces, and yellowish and hairy or woolly and glandular on the lower surfaces. The males catkins are yellowish-green and the female flowers are in short spikes in the leaf axils, appearing at the same time as the new growth of leaves. The fruit is a yellowish brown acorn up to two centimeters long with a shallow warty cup about a centimeter wide.^[7] This oak reproduces sexually via its acorns if there is enough moisture present, but more often it reproduces vegetatively by sprouting from its rhizome and root crown.^[6][4]

Quercus turbinella has been found in Arizona, New Mexico, Colorado, Utah, Nevada, southern California, and western Texas, as well as Baja California.^[8][5] In California, it occurs in the New York mountains and a few eastern California desert ranges. The populations on the desert mountains in the western Mojave desert and the inner coastal ranges are now considered Quercus john-tuckeri.^[9][10] It grows in woodland, chaparral, forest, and other habitat. It is most common in chaparral habitat in central Arizona,^[6] through the transition zone of the Mogollon Rim–White Mountains, but also southeast Arizona in the Madrean Sky Island mountain ranges of sky islands.^[11]

Quercus turbinella easily hybridizes with other oak species, including Quercus gambelii, Q. havardii, Q. arizonica, and Q. grisea.^[6] Many species of animals use it for food, with wild and domesticated ungulates browsing the foliage and many birds and mammals eating the acorns.^[6] Animals also use the shrub as cover, and mountain lions hide their kills in the thickets.^[6]

• Quercus × alvordiana