It is a large shrub or tree[5] growing to 22 metres (72 feet) tall, although where it is common in the low-elevation Sierra Nevada foothills it seldom exceeds 10 m (33 ft).

The dark-green leaves—appearing grayish from a distance—are usually small, 2–7 centimetres (1–3 inches) long,[6] thick, and often spiny-toothed at higher elevations, particularly on young trees.

[6] Although originally published by Alphonse Pyramus de Candolle as "wislizeni",[2] some sources[5] mistakenly spelled the specific epithet "wislizenii".

Currently there are two recognized varieties of interior live oak:[9] It was named for its collector, Friedrich Adolph Wislizenus (1810–1889).

It generally occurs in foothills, being most abundant in the lower elevations of the Sierra Nevada, but also widespread in the Pacific Coast Ranges—where since 1980 it has been known as a separate species Quercus parvula[13][14]—and the San Gabriel Mountains.