Tung tree
Encyclopedia
Vernicia fordii is a species of Vernicia
in the spurge
family, native to southern China
, Burma, and northern Vietnam
. Other vernacular names include Tung Oil Tree, Tung-oil Tree, Tungoil Tree, China Wood-Oil Tree, Kalo Nut Tree, 油桐 (lit. oil tung) being the formal name in Chinese.
It is a small to medium-sized deciduous
tree
growing to 20 m tall, with a spreading crown. The bark
is smooth and thin, and bleeds latex
if cut. The leaves
are alternate, simple, 4.5–25 cm long and 3.5–22 cm broad, heart-shaped or with three shallow, maple
-like lobes, green above and below, red conspicuous glands at the base of the leaf, and with a 5.5–26 cm long petiole
. The flower
s are 2.5–3.5 cm diameter, with five pale pink to purple petals with streaks of darker red or purple in the throat; it is monoecious
with individual flowers either male or female, but produced together in the inflorescence
s. The flowers appear before or with the leaves in loose, terminal clusters. The fruit
is a hard, woody pear-shaped drupe 4–6 cm long and 3–5 cm diameter, containing four or five large, oily seeds; it is green initially, becoming dull brown when ripe in autumn.
, which is derived from the seed
s of the tree. Tung oil, also called China wood oil or nut oil, has traditionally been used in lamps in China. In modern times, it is used as an ingredient in paint
, varnish
, and caulk. It is also used as a wood finish
for furniture
and other wood
en objects. After processing to remove gums in the oil, it can also be used as a motor oil. Marco Polo
wrote in the 13th century "The Chinese take some lime and chopped hemp, and these they knead together with a certain wood oil; and when the three are thoroughly amalgamated they hold like any glue, and with this mixture they pay their ships".
It has been introduced to Argentina
, Paraguay
, Thailand
, and the United States
for oil production. Just prior to World War I, a number of seeds received from the U.S. Ambassador to China were planted in California, but the young trees could not take hold in the dry climate.
David Fairchild
of the Department of Agriculture successfully introduced the tree in 1905 in the U.S. Gulf States from Florida
west to eastern Texas
.
After flourishing from the 1920s to the 1940s the American tung oil industry was wiped out by frost and hurricanes. In 1969, many of the trees were wiped out by Hurricane Camille
, and the plantations never recovered. Increased competition from overseas has ended cultivation in the United States and the tree is now listed as an invasive species
in Florida.
Global production of the fruit has risen from just over 100,000 tonnes in 1970 to almost 200,000 tonnes by 1980. Fruit yields are typically in the range of 4.5–5 tonnes per hectare. A number of cultivar
s have been selected for increased yield and small tree size, including 'Folsom', 'Cahl', 'Isabel', 'La Crosser', and 'Lampton'.
The wood of the tree is lightweight and strong, and is sometimes used as a substitute for balsa or basswood.
The Tung tree is poisonous in all of its parts, including the fruit and the seeds, although some parts of the tree have been used for medicinal purposes in the past. According to one university website, just one seed from the fruit can be fatal, and other symptoms may include vomiting, diarrhea, and slowed breathing. The leaves can also give a rash similar to that from poison ivy.
Vernicia
The genus Vernicia, commonly referred to as Tung or Tung-oil Tree, is a genus in the spurge family Euphorbiaceae, comprising three species, native to eastern and southeastern Asia....
in the spurge
Euphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
family, native to southern China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Burma, and northern Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
. Other vernacular names include Tung Oil Tree, Tung-oil Tree, Tungoil Tree, China Wood-Oil Tree, Kalo Nut Tree, 油桐 (lit. oil tung) being the formal name in Chinese.
It is a small to medium-sized deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
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...
growing to 20 m tall, with a spreading crown. The bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
is smooth and thin, and bleeds latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
if cut. The leaves
Leaf
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, simple, 4.5–25 cm long and 3.5–22 cm broad, heart-shaped or with three shallow, maple
Maple
Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...
-like lobes, green above and below, red conspicuous glands at the base of the leaf, and with a 5.5–26 cm long petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are 2.5–3.5 cm diameter, with five pale pink to purple petals with streaks of darker red or purple in the throat; it is monoecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
with individual flowers either male or female, but produced together in the inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s. The flowers appear before or with the leaves in loose, terminal clusters. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a hard, woody pear-shaped drupe 4–6 cm long and 3–5 cm diameter, containing four or five large, oily seeds; it is green initially, becoming dull brown when ripe in autumn.
Cultivation and uses
The tung tree is valued for tung oilTung oil
Tung oil or China wood oil is a drying oil obtained by pressing the seed from the nut of the tung tree . As a drying oil, tung oil hardens upon exposure to air. The resulting coating is transparent plastic-like and is exploited in most of its applications, which include wood finishing and the...
, which is derived from 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...
s of the tree. Tung oil, also called China wood oil or nut oil, has traditionally been used in lamps in China. In modern times, it is used as an ingredient in paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
, varnish
Varnish
Varnish is a transparent, hard, protective finish or film primarily used in wood finishing but also for other materials. Varnish is traditionally a combination of a drying oil, a resin, and a thinner or solvent. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss...
, and caulk. It is also used as a wood finish
Wood finishing
Wood finishing refers to the process of embellishing and/or protecting the surface of a wooden material. The process starts with surface preparation, either by sanding by hand , scraping, or planing. Imperfections or nail holes on the surface may be filled using wood putty or pores may be filled...
for furniture
Furniture
Furniture is the mass noun for the movable objects intended to support various human activities such as seating and sleeping in beds, to hold objects at a convenient height for work using horizontal surfaces above the ground, or to store things...
and other wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
en objects. After processing to remove gums in the oil, it can also be used as a motor oil. Marco Polo
Marco Polo
Marco Polo was a Venetian merchant traveler from the Venetian Republic whose travels are recorded in Il Milione, a book which did much to introduce Europeans to Central Asia and China. He learned about trading whilst his father and uncle, Niccolò and Maffeo, travelled through Asia and apparently...
wrote in the 13th century "The Chinese take some lime and chopped hemp, and these they knead together with a certain wood oil; and when the three are thoroughly amalgamated they hold like any glue, and with this mixture they pay their ships".
It has been introduced to Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, Paraguay
Paraguay
Paraguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
for oil production. Just prior to World War I, a number of seeds received from the U.S. Ambassador to China were planted in California, but the young trees could not take hold in the dry climate.
David Fairchild
David Fairchild
David Grandison Fairchild was an American botanist and plant explorer. Fairchild was responsible for the introduction of more than 200,000 exotic plants and varieties of established crops into the United States, including soybeans, pistachios, mangos, nectarines, dates, bamboos, and flowering...
of the Department of Agriculture successfully introduced the tree in 1905 in the U.S. Gulf States from Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
west to eastern Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
.
After flourishing from the 1920s to the 1940s the American tung oil industry was wiped out by frost and hurricanes. In 1969, many of the trees were wiped out by Hurricane Camille
Hurricane Camille
Hurricane Camille was the third and strongest tropical cyclone and second hurricane during the 1969 Atlantic hurricane season. The second of three catastrophic Category 5 hurricanes to make landfall in the United States during the 20th century , which it did near the mouth of the Mississippi River...
, and the plantations never recovered. Increased competition from overseas has ended cultivation in the United States and the tree is now listed as an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in Florida.
Global production of the fruit has risen from just over 100,000 tonnes in 1970 to almost 200,000 tonnes by 1980. Fruit yields are typically in the range of 4.5–5 tonnes per hectare. A number of cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
s have been selected for increased yield and small tree size, including 'Folsom', 'Cahl', 'Isabel', 'La Crosser', and 'Lampton'.
The wood of the tree is lightweight and strong, and is sometimes used as a substitute for balsa or basswood.
The Tung tree is poisonous in all of its parts, including the fruit and the seeds, although some parts of the tree have been used for medicinal purposes in the past. According to one university website, just one seed from the fruit can be fatal, and other symptoms may include vomiting, diarrhea, and slowed breathing. The leaves can also give a rash similar to that from poison ivy.