Quercus douglasii, Blue Oak (20)

If the Manzanita is “California’s plant” by virtue of its numerous species, subspecies, and hybrids that can be found practically everywhere in the state, the oak deserves the title of “California’s tree” by virtue of its dramatic presence in the landscape and its importance to the Native Californians. The Blue Oak thrives in the hot and dry areas of California. It can be found in the dry hills surrounding the Central Valley to the east and west.

Through a unique combination of survival mechanisms, the Blue Oak can live in areas that exceed 100 degrees F in the summer and that receive only 15 inches to 35 inches of rain a year (Pavlik et al, 1991). Its seeds germinate rapidly to take advantage of sparse rains, and once sprouted, grow roots incredibly quickly. Its leaves are small and chaparral like; they are woody and resist wilting. They are usually blue green and oblong with irregular lobes and entire margins. In extremely dry conditions, the Blue Oak can shed its leaves to conserve energy, but will sometimes continue to produce acorns from stored reserves of energy!

The acorns of the Blue Oak are globular and where used by Native Californians as a food source (Stuart and Sawyer, 2001). Today, however, the Blue Oak has a low commercial value because of its wood’s tendency to fracture when dried. It is also prone to rot.

The Blue Oak is found only in California (Vermevlen, 1997). In California, however, it has a wide range: it grows in 39 of the 58 counties (Pavlik et al, 1991).