Quercus lobata
valley oak, roble

Fagaceae (beech family)
California
Quercus lobata, Jasper Ridge. John Rawlings

This is the other great oak, besides coast live oak, occurring on campus as part of its natural habitat. It is a large deciduous tree, just as picturesque, with distinctly lobed leaves and long acorns. Valley oak forms the greatest tribe of U.S. oaks, and the chief valley oak lives at Covelo, California, north of Willits. In 1984, its height was measured at 163 feet, with a girth of 29 feet.

At Stanford, many old valley oaks have fallen victim to development. A fine specimen is between 708 and 712 Salvatierra Street; a younger tree is north of the Bookstore with a pepper tree and a deodar cedar. Dozens of young trees have been planted in the center divider of Quarry Road near El Camino Real. Healthy mature native oaks, however, can still be found on central campus: visit the inner court of Governor’s corner where fine examples grow (December 2010) along with blue oak and and coast live oak. In Palo Alto, see three beauties at 300 Homer Avenue, 450 Sequoia Avenue, and 3775 La Donna Street.

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

The Spanish name roble is derived, by the normal process of dissimulation, from robur, the Latin name of the common Old World deciduous oak robur with lobed leaves. Conspicuous brown balls, as big as golf balls but not much resembling an acorn, are often noticed among the foliage. They are galls, popularly known as oak-apples, that result from a wasp depositing an egg, along with some plant hormone, to stimulate the growth of a protective home for the larva. Among the litter, one may find jumping galls about a millimeter in diameter that use the same strategy as the Mexican jumping bean, namely to reach shelter from the sun; when they land in a shady spot they cease jumping. If you take some home and put them in the bedroom they quiet down, but they start jumping when a bedside lamp is lit.

Illustrations: Jasper Ridge Quercus lobata on Flickr.

About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005.