tanoak Fagaceae Notholithocarpus
densiflorus (Hook. & Arn.) P.S. Manos, C.H. Cannon, & S.H. Oh symbol: LIDE3
Leaf: Simple, alternate, persistent for 3 to 4 years, oblong, 3 to 5 inches long, stiff and leathery, margins may be entire or coarsely toothed and are often revolute. Young leaves are densely pubescent, mature leaves are dark green above and bluish white underneath and have lost most of their pubescence.
Flower: Species is monoecious; imperfect with separate sexes borne in erect aments; female aments are borne on the basal portion of an otherwise male ament, appearing with the leaves.
Fruit: Single or paired acorns about 1 inch long, caps are shallow and covered with dense bristles, the insides of the caps and the exposed portion of the nut are densely pubescent. Acorns take 2 seasons to mature.
Twig: Stout, round, covered with dense rust-colored pubescence for the first or second year, reddish brown; pith is stellate.
Bark: Mature bark is moderately thick (3/4 to 1 1/2 inches) with narrow furrows and rounded, flattened ridges sometimes breaking into square plates; reddish brown.
Form: A moderate sized tree (60 to 100 feet tall and 1 to 5 feet in diameter), commonly growing in clumps with multiple stems due to sprouts arising from underground burls. In the open, the crown is dense and rounded, in the shade it can be narrow and spire-like.
Looks like: island live oak - canyon live oak - Engelmann oak - interior live oak
Additional Range Information: Notholithocarpus densiflorus is native to North America. Range may be expanded by planting. See states reporting tanoak.
External Links: USDAFS Silvics of North America - USDAFS Additional Silvics - USDA Plants Database - USDAFS Forest Products Lab
All material © 2017 Virginia Tech Dept. of Forest Resources and Environmental Conservation; Photos and text by: John Seiler, Edward Jensen, Alex Niemiera, and John Peterson