Notholithocarpus
Encyclopedia
Notholithocarpus densiflorus, commonly known as the Tanoak or Tanbark-oak, is an evergreen
tree
in the beech
family Fagaceae
, native to the western United States
, in California
as far south as the Transverse Ranges
, north to southwest Oregon
, and east in the Sierra Nevada. It can reach 40 metres (131.2 ft) tall (though 15–25 m (49.2–82 ft) is more usual) in the California Coast Ranges, and can have a trunk diameter of 60–190 cm (23.6–74.8 in).
Tanbark-oak was recently moved into a new genus, Notholithocarpus, based on multiple lines of evidence. It is clearly not related to the Asian tropical stone oaks, Lithocarpus, but instead is an example of convergent morphological evolution. The North American tanbark-oak is most closely related to the north temperate oaks, Quercus.
are alternate, 7–15 cm (2.8–5.9 in), with toothed margins and a hard, leathery texture, and persist for 3–4 years. At first they are covered in dense orange-brown scurfy hairs on both sides, but those on the upper surface soon wear off, those on the under surface persisting longer but eventually wearing off too.
The seed
is a nut
2–3 cm (0.78740157480315–1.2 in) long and 2 cm diameter, very similar to an oak
acorn
, but with a very hard, woody nut shell more like a hazel
nut. The nut sits in a cup during its 18-month maturation; the outside surface of the cup is rough with short spines. The nuts are produced in clusters of a few together on a single stem. The nut kernel is very bitter, and is inedible for people without extensive leaching, although squirrel
s eat them.
into southwest Oregon are smaller, rarely exceeding 3 metres (9.8 ft) in height and often shrubby, with smaller leaves, 4–7 cm (1.6–2.8 in) long; these are separated as Dwarf Tanoak, Notholithocarpus densiflorus var. echinoides. The variety intergrades with the type in northwest California and southwest Oregon. Tanoak does grow on serpentine soil
s as a shrub.
prefer this nut to those of many Quercus acorn
s because it stores well due to the comparatively high tannin content.
The name Tanoak refers to its tannin
-rich bark, a type of tanbark
, used in the past for tanning leather
before the use of modern synthetic tannins.
Tanoak is one of the species most seriously affected by Sudden Oak Death
(Phytophthora ramorum), with high mortality reported over much of the species' range.
. It has a circumference of 312 inches, about 8.25 feet in diameter at breast height
, and is 121 feet tall with an average crown spread of 56 feet.
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
in the beech
Beech
Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...
family Fagaceae
Fagaceae
The family Fagaceae, or beech family, comprises about 900 species of both evergreen and deciduous trees and shrubs, which are characterized by alternate simple leaves with pinnate venation, unisexual flowers in the form of catkins, and fruit in the form of cup-like nuts. Fagaceous leaves are often...
, native to the western United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
as far south as the Transverse Ranges
Transverse Ranges
The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region that runs along the Pacific coast from Alaska to Mexico in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie between...
, north to southwest Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, and east in the Sierra Nevada. It can reach 40 metres (131.2 ft) tall (though 15–25 m (49.2–82 ft) is more usual) in the California Coast Ranges, and can have a trunk diameter of 60–190 cm (23.6–74.8 in).
Tanbark-oak was recently moved into a new genus, Notholithocarpus, based on multiple lines of evidence. It is clearly not related to the Asian tropical stone oaks, Lithocarpus, but instead is an example of convergent morphological evolution. The North American tanbark-oak is most closely related to the north temperate oaks, Quercus.
Description
The Notholithocarpus densiflorus leavesLeaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are alternate, 7–15 cm (2.8–5.9 in), with toothed margins and a hard, leathery texture, and persist for 3–4 years. At first they are covered in dense orange-brown scurfy hairs on both sides, but those on the upper surface soon wear off, those on the under surface persisting longer but eventually wearing off too.
The seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
is a nut
Nut (fruit)
A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...
2–3 cm (0.78740157480315–1.2 in) long and 2 cm diameter, very similar to an oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
, but with a very hard, woody nut shell more like a hazel
Hazel
The hazels are a genus of deciduous trees and large shrubs native to the temperate northern hemisphere. The genus is usually placed in the birch family Betulaceae, though some botanists split the hazels into a separate family Corylaceae.They have simple, rounded leaves with double-serrate margins...
nut. The nut sits in a cup during its 18-month maturation; the outside surface of the cup is rough with short spines. The nuts are produced in clusters of a few together on a single stem. The nut kernel is very bitter, and is inedible for people without extensive leaching, although squirrel
Squirrel
Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots , flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa and have been introduced to Australia...
s eat them.
Notholithocarpus densiflorus var. echinoides
Members of populations in interior California (in the northern Sierra Nevada) and the Klamath MountainsKlamath Mountains
The Klamath Mountains, which include the Siskiyou, Marble, Scott, Trinity, Trinity Alps, Salmon, and northern Yolla-Bolly Mountains, are a rugged lightly populated mountain range in northwest California and southwest Oregon in the United States...
into southwest Oregon are smaller, rarely exceeding 3 metres (9.8 ft) in height and often shrubby, with smaller leaves, 4–7 cm (1.6–2.8 in) long; these are separated as Dwarf Tanoak, Notholithocarpus densiflorus var. echinoides. The variety intergrades with the type in northwest California and southwest Oregon. Tanoak does grow on serpentine soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
s as a shrub.
Uses
Some California Native AmericansNative Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
prefer this nut to those of many Quercus acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
s because it stores well due to the comparatively high tannin content.
The name Tanoak refers to its tannin
Tannin
A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.The term tannin refers to the use of...
-rich bark, a type of tanbark
Tanbark
Tanbark is the bark of certain species of tree. It is traditionally used for tanning hides.The words "tanning", "tan," and "tawny" are derived from the Medieval Latin tannare, "to convert into leather."...
, used in the past for tanning leather
Leather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...
before the use of modern synthetic tannins.
Tanoak is one of the species most seriously affected by Sudden Oak Death
Sudden oak death
Sudden Oak Death is the common name of a disease caused by the oomycete plant pathogen Phytophthora ramorum. The disease kills oak and other species of tree and has had devastating effects on the oak populations in California and Oregon as well as also being present in Europe...
(Phytophthora ramorum), with high mortality reported over much of the species' range.
Big tree
Currently the largest known Tanoak specimen is on private timberland near the town of Ophir, OregonOphir, Oregon
Ophir is an unincorporated community in Curry County, Oregon, United States. Although it is unincorporated, it has a post office with a ZIP code of 97464. Ophir lies at the intersection of Oregon Route 515 and U.S. Route 101, northeast of Nesika Beach....
. It has a circumference of 312 inches, about 8.25 feet in diameter at breast height
Diameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements....
, and is 121 feet tall with an average crown spread of 56 feet.