Interior live oak

The Interior live oak, Quercus wislizenii is an evergeen oak, highly variable and often shrubby, found in the large areas of California in the United States. It also occurs south into northern Baja California in Mexico. It generally occurs in foothills, being most abundant in the lower altitudes of the Sierra Nevada, but also widespread in the Coast Ranges and the San Gabriel Mountains.

The dark-green leaves are usually small, thick and spiny-toothed.

The Interior live oak is classified in the red oak section (Quercus sect. Lobatae). Several hybrids between Interior live oak and other red oak species have been documented. Hybrids with California live oak (Q. agrifolia) are known in many areas in coastal California. It also hybridizes with Nuttall's scrub oak (Q. dumosa) and California black oak (Q. kelloggii). All these oak species show evidence of introgression with one another.