Quercus douglasii, commonly known as the blue oak, is a deciduous tree native to California. It typically grows in dry, hilly areas and can reach heights of 30 to 60 feet. The tree is characterized by its distinctive blue-green leaves, which are lobed and can vary in shape. The blue oak produces acorns that are an important food source for wildlife, including birds and mammals. It thrives in well-drained soils and is adapted to withstand drought conditions, making it a resilient species in its native habitat.