Tanoak
Notholithocarpus densiflorus
Tanoak is a narrow, evergreen broadleaf tree reaching up to 40 meters tall in the California Coast Ranges, though it more commonly grows 15 to 25 meters tall, or even shorter. The thick central trunk, coated in fissured gray-brown bark, can reach a diameter of 60 to 190 centimeters. The crown varies from narrow to broad and rounded, depending on light exposure. The gray-green leaves are thick and leathery with sharply toothed edges. Young leaves are covered with dense orange-brown hairs, which rub off, though they persist on the undersides, becoming fuzzy-white. The hard, woody acorns, 2-3 cm long and 2 cm wide, grow in clumps. The acorn cup is coated in short spikes.
Basic Information
Member of the Fagaceae, beech, family, which includes oak trees, though it is in a separate genus than the true oaks in Quercus
Broadleaf evergreen tree or shrub
Can live up to 400 years
Slow-growing, though be quite tall
The largest known tanoak specimen is 2.51 meters (8 ft 3 in) wide and 37 meters (121 ft) tall
There are two recognized varieties:
Notholithocarpus densiflorus var. echinoides — grows in northern, southern and central California
Notholithocarpus densiflorus var. densiflorus — bush tanoak; grows in high elevations in central and northern California; diminutive size, growing below 3 meters; more common variety
Habitat
Native to the coastal regions of Oregon and California
In California, it is found only so far south as the Transverse Ranges and as far east as the Sierra Nevadas
Found primarily on woody slopes in
Often found on moist banks and north face facing slopes below 5000 ft of the elevation
Ecological Role
The nuts are eaten by various animals, including squirrels, deer and bears
Provides shelter to many animals, such as woodpeckers, chipmunks, and northern flying squirrels
Fine hairs on the young leaves and twigs discourage deer
Reproduction
Blooms from June to August
The tree is monoecious, having both male and female reproductive organs on the sam tree, though the flowers are unisexual
The acorns have an 18-month maturation
Alternative Names
Mutant Tanoak, tanbark-oak
The “Old California Spanish” name was ‘cascalote’
The Rumsen and Mutsun name was ‘xoppow’
Rumsen and Mutsun are two Ohlone languages
Formerly known by the scientific name Lithocarpus densiflorus
Historical Uses
For tribes throughout the tanoak’s range, such as the Ohlone, Hahwunkwut , Hupa, Karok, and Pomo, the acorns were a major food source
Stored for use during the winter
Made into pancakes, bread, mush, soup, or gruel, which was flavored with venison and herbs
Native peoples often went on gathering trips, during which they would camp in the groves
The Kashaya Pomo spun the strung acorns in a special way to make music
The Ohlone also used the plant medicinally:
An infusion of bark used to wash face sores
An infusion of the bark held in the mouth to tighten loose teeth
The bark was also used to make dye
Additional Information
Tan oak bark was once the main commercial source of tannin in the west
Tannin was used to cure leather
Tanoak is seriously affected by the pathogen "sudden oak death,” Phytophthora ramorum
