The Quercus douglasii Blue Oak is a unique oak tree only found in California. It is endemic to the foothills surrounding the Central Valley of California and certain locations in the California Coast Ranges. Individual trees over 500 years old have been recorded making it one of the oldest trees in the area. Recent research has found several unlogged stands of Blue Oak woodlands, suggesting there may be over 500,000 acres of such old growth forests in California. The name Blue Oak derives from the dark blue-green tint of its leaves, which are deciduous, 4–10 cm long and entire or shallowly lobed. Quercus douglasii prefers dry soil and plenty of sunlight, making it the most drought-tolerant of California's deciduous oaks. It also serves as an essential component of mixed oak forests and savanna, which support a diversity of ecological biodiversity within the California Floristic Province.
