drought, the leaf color is more pronounced. Trees can also drop their leaves in summer rather than fall in dry years, but usually continue to develop their acorns through the fall. Drought may cause trees not to flower in spring. Gall wasps Author Ron Russo writes that Q. douglasii hosts the "largest number of known species" of gall wasps, at more than 50. The wasps trigger the formation of oak galls in a wide variety of shapes, colors, and sizes. Sudden oak death resistance As of 2002, the disease known as sudden oak death, caused by the oomycete Phytophthora ramorum, had not been found in Quercus douglasii or any members of the white oak group. An experiment showed that Q. douglasii and Q. lobata (another white oak) appeared to be resistant to the pathogen. Uses Native Californians commonly gathered Quercus douglasii acorns, which they considered good-tasting, and processed them into acorn flour. They made baskets out of blue oak seedlings, utensils such as bowls from the wood, and dye from the acorns. Commercially, the blue oak is mainly limited to use as firewood. The acorns are eaten by wildlife and livestock. They can be eaten but, if bitter, may need to have the tannins leached. See also Quercus × alvordiana Notes References douglasii Endemic flora of California Natural history of the California Coast Ranges Natural history of the Central Valley (California) Plants described in 1840 Trees of Mediterranean climate Garden plants of North America Ornamental trees