California black oak Fagaceae Quercus
Leaf: Alternate, simple, deciduous; pinnately lobed (usually 7 lobes), each lobe is 3-toothed and bristle-tipped, sinuses may be shallow or deep; oblong or obovate in shape, 3 to 6 inches long; yellow-green, smooth and lustrous above and paler below.
Flower: Species is monoecious; inconspicuous, male and female flowers borne in separate aments (catkins), appearing with the leaves.
Fruit: Acorn, 1 to 2 1/2 inches long, reddish brown; cap is deep, covering about half the nut. Require 2 seasons to mature.
Twig: Reddish brown, ridged, smooth or minutely pubescent; terminal buds are large, pointed and clustered at the ends of the twigs.
Bark: Initially smooth and dark gray or black; when mature turning dark brown to black, broad, irregularly plated ridges, about 1 inch thick.
Form: A medium sized broad-leaved deciduous tree (40 to 80 feet tall and 1 to 2 1/2 feet in diameter) with an open, rounded top. At high elevations, it may occur as a large shrub.
Looks like: Oregon white oak