palo alto trees

Quercus Lobata: The Tasso Street Oak Identified

[29 September 2002]

Today, I started trying to figure out exactly what kind of oak we have across the street from us (and also pictured below) at 2341 Tasso Street in Palo Alto.

Oak
Tasso Street
Palo Alto, California
29 September 2002
more photos of the tree

There are apparently lots of species of oak trees.

I don't think it is a Holly Oak or a Coast Live Oak, which are the two most common types in Palo Alto, according to a recent city publication. A Holly Oak has pointy tipped leaves that look like, well, holly—according to this page, which also includes a picture of leaves looking similar to my oak that are labelled "Mediterranean Oak". I ruled out the Coast Live Oak possibility by consulting this page.

Other guesses are Bur Oak, and White Oak (possibly Oregon White Oak). The leaves of the tree identified here as a Bur Oak look similar to me. The Oregon White Oak is shown there too, but not with a good picture of its leaves.

Here are more photos of this tree.

[30 September 2002]

Today, I got a helpful response from to an email I sent to the California Oak Foundation.

It looks like a white oak -- are the acorns long and skinny or short and round? We invite you to visit our website at http://www.californiaoaks.org/html/links.html where you’ll find on our Links page UC Berkeley’s Digital Library Project. Simply type in what you’re looking for (suggest just typing in quercus) and let it search for you. There is an extensive library of photos to choose from including several with leaves and acorns to help identify. Good luck.

California Oak Foundation
1212 Broadway, Suite 810
Oakland, CA 94612
phone: 510-763-0282
fax: 510-208-4435
e-mail: oakstaff@californiaoaks
www.californiaoaks.org

The acorns are long and skinny, I replied.

Long and skinny acorns probably mean it's a valley oak, which would be the norm in Palo Alto. Try entering quercus lobata in the UC Berkeley website at http://elib.cs.berkeley.edu/photos and see if it matches what you've got.

It matched.

I also went to Borders bookstore and bought a book called Oaks of California, by Bruce M Pavlik, Pamela C Muick, Sharon G Johnson, and Marjorie Popper. It was published by Cachuma Press—and the California Oak Foundation!—(fourth Printing), January 2000.

Here's are some excerpts from the book:

Valley Oak (Quercus lobata)

Valley Oak is the monarch of California oaks by virtue of its size, age, and beauty. The largest trees have massive trunks, sometimes six or seven feet in diameter, that support a body of great limbs and craggy branches. These may rise more than 100 feet above the ground, shielded by a thick bark that has the color of pewter and the blocky texture of alligator hide.

Spherical insect galls are densely clustered on young branches [Yep. It's got them. Thane, add photos here] within the leafy canopy...

...it can achieve high rates of photosynthesis and growth. As a result, many rather impressive trees, with trunks three or four feet in diameter, are relatively young—only 150 to 250 years old...

Valley oak has been given a variety of names over the years. The species reminded Spanish explorers of the majestic white oaks of Europe and so the same name roble was applied. Botantists were struck by the deeply sinuous outline of the leaves and formally declared the species as lobata..."White oak," "Bottom oak," "swamp oak," and "water oak" are other names that still enjoy regional use. The scientific name Quercus lobata is the only one with universal acceptance.

The name "white oak" carries additional significance to botanists. It not only belongs to valley oak, but also refers to a number of oak species that share some important characteristics with valley oak. Similar leaves, wood, bark, and acorns mean that that these oak species form a lineage with a common evolutionary history. The white oak evolutionary lineage, formally named as the subgenus Lepidobalanus, consists of valley oak and a rather large number of other oak species within and beyond California's borders.

After reading this passage and looking at more photos, I'm satisfied it is a Valley Oak.

Valley Oak
Tasso Street
Palo Alto, California
29 September 2002

Oak
Tasso Street
Palo Alto, California
29 September 2002