Quercus turbinella is a species of oak known by the common names Sonoran scrub oak, shrub live oak, and grey oak. It is native to northwestern Mexico and the southwestern United States from far eastern California to southwest Colorado, Rio Grande New Mexico, to west Texas.
Quercus turbinella grows in woodland, chaparral, forest, and other habitat. It is most common in chaparral habitat in central Arizona, through the transition zone of the Mogollon Rim–White Mountains, but also southeast Arizona in the Madrean Sky Island mountain ranges of sky islands.
Quercus turbinella is a shrub growing two to five meters in height but sometimes becoming treelike and exceeding six meters. 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 three centimeters long by two 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. 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.
This oak easily hybridizes with other oak species, including Quercus gambelii and Q. grisea. Many species of animals use it for food, with wild and domesticated ungulates browsing the foliage and many birds and mammals eating the acorns. Animals also use the shrub as cover, and mountain lions hide their kills in the thickets.
|Wikimedia Commons has media related to Quercus turbinella.|
- Little. Atlas of United States Trees, Volume 3, Minor Western Hardwoods, Little, Elbert L, 1976, US Government Printing Office. Library of Congress No. 79-653298. Map 147, Quercus turbinella.