Quercus wislizeni interior live oak

Flat, spiny leaves of Quercus wislizeni leaves with immature acorns; Campus Drive and Santa Teresa Street. Sairus Patel, 15 Jul 2023

Quercus wislizeni leaves and acorn. From: Howard E. McMinn & Evelyn Maino, An Illustrated Manual of Pacific Coast Trees

The leaves are similar to those of coast live oak, but are flat, not concave, and do not have coast live oak’s characteristic tufts of hairs at the vein axils on the undersides. Otherwise, the leaf shape is quite variable. Hybrids of the two species are not uncommon. Interior live oak has been planted on campus in recent years. These young trees have a very upright, smooth gray trunk. Their crown structure is somewhat gangly. See some scattered along the Serra Street median near the Pampas Lane intersection, and a couple at the northwest corner of the intersection of Campus Drive with Santa Teresa Street (2016). The east side of the Neurosciences building has three placed among the valley oaks (2020).

What was thought to be variety frutescens (dwarf interior live oak) at Jasper Ridge Biological Preserve is now considered Quercus parvula var. shrevei.