Shrub

Notholithocarpus densiflorus var. echinoides (Fagaceae) is the shrub form of tanoak, forming a densely branched, compact broadleaf evergreen to about 10 feet tall. Leaves are similar to the tree form but somewhat smaller (6 to 13 cm) with fewer teeth. The variety name echinoides (from Greek for hedgehog) refers to the bristly acorn caps characteristic of the species.

Shrub tanoak grows in sun for the most compact habit, though it tolerates light shade. Site requirements and disease susceptibility parallel the tree form, including vulnerability to sudden oak death (Phytophthora ramorum) and Armillaria root rot. The compact size makes it suitable for garden use where the full-sized tree would be too large. Hardy in Zones 7a to 8b.