A deciduous tree usually under 40 ft high, but occasionally taller in sheltered places, with a smooth, ashy bark; buds ovoid, with deciduous stipules; young stems densely downy, slowly becoming glabrous. Leaves bluish green, rigid, falling late in the autumn, oblong or elliptic, obtuse at the apex, broadly cuneate to almost truncate at the base, 2 to 3 in. long, 1 to 13⁄4 in. wide, margins varying from sinuately toothed to almost entire, glabrous above except for scattered stellate hairs, finely hairy beneath; petiole less than 1⁄2 in. long. Fruits solitary or paired, almost sessile. Acorn ovoid or elongate-ovoid, 1 in. or slightly more long; cup enclosing only the base of the acorn, with appressed, downy scales.
Native of California up to 4,000 ft, often associated with evergreen oaks and Pinus sabiniana. Although apparently quite hardy, and with strikingly sea-green leaves, it is uncommon in cultivation. Some authorities place it in the section Erythrobalanus, though in most of its characters it agrees better with the section Quercus, in which it is retained by Camus (Les Chênes, Vol. III, p. 1252).