Notholithocarpus densiflorus
Common name: 
no-thoh-lith-o-KAR-pus des-i-FLO-rus
Lithocarus densiflorus
Native to (or naturalized in) Oregon: 
  • Broadleaf evergreen tree/shrub, 20-30(90) ft [6-9(27) m] high, varying from narrow and conical to broad and rounded; sometimes a shrub, less than 10 ft (3m) [N. d. var. echinoides, Shrub Tanoak].  Leaves oblong, 6-13 cm long, 2-6 cm wide, thick, leathery, wavy-toothed border, shiny light green, whitish beneath (tawny pubescence when first unfolded), margin coarsely toothed to entire, often revolute (rolled under).  Flowers are unisexual, male (pollen) flowers are in catkins 5-10 cm long, white but turning rust colored, with an unpleasant odor; greenish-yellow female (seed) flowers are found at the base of catkins.  Fruit (acorns) are egg-shaped, 2-3 cm long, shallow saucer-shaped cup, covered with dense bristles; mature in the second year.
  • Sun or partial shade, very shade tolerant.  Best in rich, moist soil.  Stands some drought when established.  One of the few evergreen, broad-leaved trees for the Willamette Valley.
  • Hardy to USDA Zone 7      Native range from southwest Oregon (Cascade Mountains through the Klamath Mountains) to southern California.
  • Note:  The scientific name of Tanoak was Lithocarpus densiflorus, but it is now in the genus, Notholithocarpus, hence Notholithocarpus densiflorus. The taxonomic change is based on molecular and other lines of evidence.  Tanoak is not related to the Asian tropical stone oaks, i.e., Lithocarpus, but rather it is more closely related to the northern temperate oaks, Quercus.
  • Notholithocarpusnotho, false; lithocarpus         densiflorus: densely flowered
  • Its "acorns" are oak-like, but is flowers are like those of chestnuts or chinkapins.  Native Americans removed the shells of the acorn, washed the seeds in hot water to remove the tannins, and then ground them into flour.
Click image to enlarge
  • plant habit, tree form

    plant habit, tree form

  • leaves


  • leaf


  • leaf


  • leaves, young catkins and fruit

    leaves, young catkins and fruit

  • developing fruit

    developing fruit

  • leaves, catkins and developing fruit

    leaves, catkins and developing fruit

  • male catkin flowers

    male catkin flowers

  • young and maturing fruit

    young and maturing fruit