Quercus kelloggii is commonly called California Black Oak.  It is sometimes known simply as black oak or Kellogg oak.  Kelloggii is in the red oak family and is native to western North America. It is closely related to black oaks in other parts of North America.

 Quercus kelloggiiis deciduous growing from 30 feet to as much as 90 feet tall.  Its bark is a dark brown to nearly black color with broad irregular ridges.  Kelloggii will flower in late spring and produces abundant crops of acorns.  It is said that prolific acorn production from many quercus including Kelloggii was an important food source for Native Americans.

 Kelloggii species have also been known to grow in a shrubby form sometimes called scrub-oak. In open growing areas the top of Kelloggii is broad and rounded with the lower branches nearly touching the ground. The lower areas of the trunks of trees that grow close together are usually free of branches. The bark is thin and smooth on young trees but becomes thick with ridges as it ages.  Kelloggii oak grows vertical roots which can penetrate all the way to bedrock.  Large laterally spreading roots can extend from vertical roots producing a number of surface roots.