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Tree of heaven

Tree of heaven

Overview
Ailanthus altissima , commonly known as tree of heaven, ailanthus, or in Standard Mandarin
Standard Mandarin
Standard Mandarin, or Standard Chinese, known by various names to native speakers, is the official modern Chinese spoken language used in mainland China and Taiwan, and is one of the four official languages of Singapore....

 as chouchun , is a 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 in the Simaroubaceae
Simaroubaceae
The Simaroubaceae is a small, mostly tropical, family in the order Sapindales. In recent decades it has been subject to much taxonomic debate, with several small families being split off....

 family. It is native to both northeast and central China
China
China is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....

 and Taiwan
Taiwan
Taiwan , also known as Formosa , is the largest island of the Republic of China in East Asia. Taiwan is located east of the Taiwan Strait, off the southeastern coast of mainland China...

. Unlike other members of the genus Ailanthus
Ailanthus
Ailanthus is a genus of trees belonging to the family Simaroubaceae, in the order Sapindales...

, it is found in temperate climates rather than the tropics. The tree grows rapidly and is capable of reaching heights of 15 metres (50 ft) in 25 years.
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Encyclopedia
Ailanthus altissima , commonly known as tree of heaven, ailanthus, or in Standard Mandarin
Standard Mandarin
Standard Mandarin, or Standard Chinese, known by various names to native speakers, is the official modern Chinese spoken language used in mainland China and Taiwan, and is one of the four official languages of Singapore....

 as chouchun , is a 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 in the Simaroubaceae
Simaroubaceae
The Simaroubaceae is a small, mostly tropical, family in the order Sapindales. In recent decades it has been subject to much taxonomic debate, with several small families being split off....

 family. It is native to both northeast and central China
China
China is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....

 and Taiwan
Taiwan
Taiwan , also known as Formosa , is the largest island of the Republic of China in East Asia. Taiwan is located east of the Taiwan Strait, off the southeastern coast of mainland China...

. Unlike other members of the genus Ailanthus
Ailanthus
Ailanthus is a genus of trees belonging to the family Simaroubaceae, in the order Sapindales...

, it is found in temperate climates rather than the tropics. The tree grows rapidly and is capable of reaching heights of 15 metres (50 ft) in 25 years. However, the species is also short lived and rarely lives more than 50 years.

In China, the tree of heaven has a long and rich history. It was mentioned in the oldest extant Chinese dictionary and listed in countless Chinese medical texts for its purported ability to cure ailments ranging from mental illness to balding. The roots, leaves and bark are still used today in traditional Chinese medicine
Traditional Chinese medicine
Traditional Chinese Medicine, also known as TCM , includes a range of traditional medical practices originating in China. Although well accepted in the mainstream of medical care throughout East Asia, it is considered an alternative medical system in much of the western world.TCM practices include...

, primarily as an astringent
Astringent
An astringent substance is a chemical that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...

. The tree has been grown extensively both in China and abroad as a host plant for the ailanthus silkmoth, a moth involved in silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from cocoons made by the larvae of the mulberry silkworm Bombyx mori reared in captivity...

 production. Ailanthus has become a part of western culture as well, with the tree serving as the central metaphor and subject matter of the best-selling American novel A Tree Grows in Brooklyn by Betty Smith
Betty Smith
For other uses, see Betty Smith .Betty Smith, née Elisabeth Wehner , was an American author.-Biography:...

.

The tree was first brought from China to Europe in the 1740s and to the United States in 1784. It was one of the first trees brought west during a time when chinoiserie
Chinoiserie
Chinoiserie, a French term, signifying "Chinese-esque", refers to a recurring theme in European artistic styles since the seventeenth century, which reflect Chinese artistic influences...

was dominating European arts, and was initially hailed as a beautiful garden specimen. However, enthusiasm soon waned after gardeners became familiar with its suckering
Basal shoot
A basal shoot, root sprout, adventitious shoot, water sprout or sucker is a shoot or cane which grows from a bud at the base of a tree or shrub or from its roots. Root suckers may emerge some distance from the originating plant such as in Rhus spp, some Prunus species and Embothrium species...

 habits and its foul smelling odour. Despite this, it was used extensively as a street tree during much of the 19th century. Outside of Europe and the United States, the plant has been spread to many other areas beyond its native range. In a number of these, it has become an invasive species
Invasive species
'Invasive species' is a phrase with several definitions. The first definition expresses the phrase in terms of non-indigenous species that adversely affect the habitats they invade economically, environmentally or ecologically...

 due to its ability to quickly colonise disturbed areas and suppress competition with allelopathic
Allelopathy
Allelopathy is a biological phenomenon that is characteristic of some plants, algae, bacteria, coral and fungi by which they produce certain biochemicals that influence the growth and development of other organisms. The biochemicals, called allelochemicals can have a beneficial or detrimental...

 chemicals. It is considered a noxious weed in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...

, the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...

 and several countries in southern
Southern Europe
The term Southern Europe, at its most general definition, is used to mean "all countries in the south of Europe". However, the concept, at different times, has had different meanings, providing additional political, linguistic and cultural context to the definition in addition to the typical...

 and eastern Europe
Eastern Europe
Eastern Europe is a region lying in the Eastern part of Europe. The term is highly context-dependent and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...

. The tree also resprouts
Basal shoot
A basal shoot, root sprout, adventitious shoot, water sprout or sucker is a shoot or cane which grows from a bud at the base of a tree or shrub or from its roots. Root suckers may emerge some distance from the originating plant such as in Rhus spp, some Prunus species and Embothrium species...

 vigorously when cut, making its eradication difficult and time consuming. In many urban areas, it has acquired the derisive nicknames of "ghetto palm" and "stink tree".

Description


A. altissima is a medium-sized tree that reaches heights between 17 and 27 metres (56 and 90 ft) with a diameter at breast height of about 1 metre (40 in). 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 light grey, often becoming somewhat rougher with light tan fissures as the tree ages. The twigs are stout, smooth to lightly pubescent, and reddish or chestnut in colour. They have lenticel
Lenticel
A lenticel is an airy aggregation of cells within the structural surfaces of the stems, roots, and other parts of vascular plants. It functions as a pore, providing a medium for the direct exchange of gasses between the internal tissues and atmosphere, thereby bypassing the periderm, which would...

s as well as heart-shaped leaf scars (i.e. a scar left on the twig after a leaf falls) with many bundle scars (i.e. small marks where the veins of the leaf once connected to the tree) around the edges. The bud
Bud
thumb|right|Flower buds have not yet bloomed into a full-size flower.In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of the stem...

s are finely pubescent, dome shaped, and partially hidden behind the petiole
Petiole (botany)
In botany, the petiole is the small 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...

, though they are completely visible in the dormant season at the sinuses of the leaf scars. The branches are light to dark gray in colour, smooth, lustrous, and containing raised lenticels that become fissures with age. The ends of the branches become pendulous. All parts of the plant have a distinguishing strong odour that is often likened to rotting peanuts or cashews.

The leaves
Leaf
In botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin. There is continued debate about whether the flatness of leaves evolved to expose the chloroplasts to more light or to increase the absorption of carbon dioxide. In...

 are large, odd- or even-pinnate
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...

ly compound, and arranged alternately on the stem. They range in size from 30 to 90 cm (1 to 3 ft) in length and contain 10–41 leaflets organised in pairs, with the largest leaves found on vigorous young sprouts. The rachis
Rachis
The rachis is the main axis of the inflorescence, or spike, of wheat and other cereals, to which the spikelets are attached. It is also the part of the axis that the pinnae are attached to in ferns, the main stem of a compound leaf , or the main axis in compound inflorescences in other...

 is light to reddish-green with a swollen base. The leaflet
Leaflet
A leaflet in botany is a part of a compound leaf. A leaflet may resemble an entire leaf, but it is not borne on a stem as a leaf is, but rather on a vein of the whole leaf. Compound leaves are common in many plant families...

s are ovate-lanceolate
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...

 with entire margins, somewhat asymmetric and occasionally not directly opposite to each others. Each leaflet is 5 to 18 cm (2 to 7 in) long and 2.5 to 5 cm (1 to 2 in) wide. They have a long tapering end while the bases have two to four teeth, each containing one or more glands at the tip. The leaflets' upper sides are dark green in colour with light green veins, while the undersides are a more whitish green. The petioles are 5 to 12 mm (0.2 to 0.5 in) long. The lobed bases and glands distinguish it from similar sumac species.
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 mediate the union of male sperm with female ovum in order to produce seeds...

s are small and appear in large panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches ....

s up to 50 cm (20 in) in length at the end of new shoots. The individual flowers are yellowish green to reddish in colour, each with five petal
Petal
A petal is one member or part of the corolla of a flower. The corolla is the name for all of the petals of a flower; the inner perianth whorl, term used when this is not the same in appearance as the outermost whorl and is used to attract pollinators based on its bright color...

s and sepal
Sepal
A sepal is a part of the flower of angiosperms . Sepals in most flowers are green and lie under the more conspicuous petals. As a collective unit the sepals form a calyx, whereas the collection of petals is called the corolla...

s. The sepals are cup-shaped, lobed and united while the petals are valvate (i.e. they meet at the edges without overlapping), white and hairy towards the inside. They appear from mid-April in the south of its range to July in the north. A. altissima is dioecious
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 male and female flowers being borne on different individuals. Male trees produce three to four times as many flowers as the females, making the male flowers more conspicuous. Furthermore, the male plants emit a foul-smelling odour while flowering to attract pollinating insects. Female flowers contain ten (or rarely five through abortion) sterile stamen
Stamen
The stamen is the male organ of a flower. Each stamen generally has a stalk called the filament , and, on top of the filament, an anther , and pollen sacs,...

s (stamenoides) with heart-shaped anthers. The pistil is made up of five free carpels (i.e. they are not fused), each containing a single ovule
Ovule
Ovule literally means "small egg." In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integuments forming its outer layer, the nucellus , and the megaspore-derived female gametophyte in its center...

. Their styles are united and slender with star-shaped stigma
Gynoecium
The gynoecium is a term with several meanings in botanical usage. In reference to mosses; liverworts; and hornworts, gynoecium refers to a cluster of archegonia and any associated modified leaves or stems present on a gametophyte shoot...

s. The male flowers are similar in appearance, but they of course lack a pistil and the stamens do function, each being topped with a globular anther and a glandular green disc. The seed
Seed
A seed , referred to as a kernel in some plants, 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 borne on the female trees are 5 mm in diameter and each is encapsulated in a samara
Samara (fruit)
A samara is a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit and indehiscent . They are winged achenes...

 that is 2.5 cm long (1 in) and 1 cm (0.4 in) broad, appearing July though August, but usually persisting on the tree until the next spring. The samara is twisted at the tips, making it spin as it falls and assisting wind dispersal. The females can produce huge amounts of seeds, normally around 30,000 per kilogram (14,000/lb
Pound (mass)
The pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement...

) of tree.

Taxonomy


The first scientific descriptions of the tree of heaven were made shortly after it was introduced to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...

 by the French Jesuit Pierre Nicholas d'Incarville. D'Incarville had sent seeds from Peking via Siberia
Siberia
Siberia , is the vast region constituting almost all of Northern Asia and for the most part currently serving as the massive central and eastern portion of the Russian Federation, having served in the same capacity previously for the USSR from its beginning, and the Russian Empire beginning in the...

 to his botanist friend Bernard de Jussieu
Bernard de Jussieu
Bernard de Jussieu was a French naturalist, younger brother of Antoine de Jussieu.Bernard de Jussieu was born in Lyon...

 in the 1740s. The seeds sent by d'Incarville were thought to be from the economically important and similar looking Chinese varnish tree (Toxicodendron vernicifluum), which he had observed in the lower Yangtze region, rather than the tree of heaven. D'Incarville attached a note indicating this, which caused much taxonomic confusion over the next few decades. In 1751, Jussieu planted a few seeds in France
France
France , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...

 and sent others on to Philip Miller
Philip Miller
Philip Miller was a botanist of Scottish descent.Miller was chief gardener at the Chelsea Physic Garden from 1722 until he was pressured to retire shortly before his death...

, the superintendent at the Chelsea Physic Garden
Chelsea Physic Garden
The Chelsea Physic Garden was established as the Apothecaries’ Garden in London, England in 1673. It is the second oldest botanical garden in Britain, after the University of Oxford Botanic Garden, which was founded in 1621.Its rock garden is the oldest English garden devoted to alpine plants...

, and to Philip C. Webb, the owner of an exotic plant garden in Busbridge
Busbridge
Busbridge is a civil parish and village in the borough of Waverley in Surrey. It has a population of 758. It forms part of the Waverley ward of Bramley, Busbridge and Hascombe....

, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...

.

Confusion in naming began when the tree was described by all three men with three different names. In Paris, Linnaeus gave the plant the name Rhus succedanea, while it was known commonly as grand vernis du Japon. In London the specimens were named by Miller as Toxicodendron altissima and in Busbridge it was dubbed in the old classification system as Rhus Sinese foliis alatis. There are extant records from the 1750s of disputes over the proper name between Philip Miller and John Ellis
John Ellis
-Politics:* Sir John Ellis, 1st Baronet , British Member of Parliament for Mid Surrey 1884–1885, Kingston 1885–1892* John Ellis , Irish Fianna Fáil politician...

, curator of Webb's garden in Busbridge. Rather than the issue being resolved, more names soon appeared for the plant: Jakob Friedrich Ehrhart
Jakob Friedrich Ehrhart
Jakob Friedrich Ehrhart was a German botanist, a pupil of Carolus Linnaeus at Uppsala University, and later Director of the Botanical Garden of Hannover, where he produced several major botanical works between 1780-1793. Ehrhart was the first author to use the rank of subspecies in botanical...

 observed a specimen in Utrecht
Utrecht (province)
Utrecht is the smallest province of the Netherlands, and is located in the center of the country. It is bordered by the Eemmeer in the north, Gelderland in the east, the river Rhine in the south, South Holland in the west, and North Holland in the northwest...

 in 1782 and named it Rhus cacodendron.

Light was shed on the taxonomic status of ailanthus in 1788 when René Louiche Desfontaines
René Louiche Desfontaines
René Louiche Desfontaines was a French botanist.Desfontaines was born near Tremblay in Brittany. He attended the Collège de Rennes and in 1773 went to Paris to study medicine. His interest in botany originated from lectures at the Jardin des Plantes given by Louis Guillaume Lemonnier...

 observed the samaras of the Paris specimens, which were still labelled Rhus succedanea, and came to the conclusion that the plant was not a sumac
Sumac
Sumac is any one of approximately 250 species of flowering plants in the genus Rhus and related genera, in the family Anacardiaceae....

. He published an article with an illustrated description and gave it the name Ailanthus glandulosa, placing it in the same genus as the tropical species then known as A. integrifolia (white siris, now A. triphysa
Ailanthus triphysa
Ailanthus triphysa is an Asian and Australian rainforest tree.-Distributon:It occurs in India, Sri Lanka, China, Malaysia, Burma, Thailand, Philippines, Indonesia and Vietnam...

). The name is derived from the Ambonese
Ambonese
The Ambonese, also known as South Moluccans, are an Indonesian ethnic group of mixed Malay-Papuan origin. They are mostly Christians or Muslims. Ambonese are from Ambon Island in Maluku, an island group east of Sulawesi and north of Timor in Indonesia. The predominant language of the island is...

 word ailanto, meaning "heaven-tree" or "tree reaching for the sky". The specific glandulosa, referring to the glands on the leaves, persisted until as late as 1957, but it was ultimately made invalid as a later homonym at the species level. The current species name comes from Walter T. Swingle who was employed by the United States Department of Plant Industry. He decided to transfer Miller's older specific name into the genus of Desfontaines, resulting in the accepted name Ailanthus altissima. Altissima is Latin for "tallest", and refers to the sizes the tree can reach. The plant is sometimes incorrectly cited with the specific epithet in the masculine (glandulosus or altissimus), which is incorrect since botanical, like Classical Latin
Classical Latin
Classical Latin in simplest terms is the sociolinguistic register of the Latin language regarded by the enfranchised and empowered populations of the late Roman republic and the Roman empire as good Latin. Most writers during this time made use of it...

, treats most tree names as feminine.

There are three varieties
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: As such, it gets a ternary name .A variety will have an appearance distinct from other varieties, but will hybridize freely with those other varieties...

 of A. altissima:
  • A. altissima var. altissima, which is the type variety and is native to mainland China
    Mainland China
    Mainland China, Continental China, the Chinese mainland or simply the mainland, is a geopolitical term that refers to the area under the jurisdiction of the People's Republic of China , excluding Hong Kong and Macau, which are under the jurisdiction of the PRC but run on different economic and...

    .
  • A. altissima var. tanakai, which is endemic to northern Taiwan
    Taiwan
    Taiwan , also known as Formosa , is the largest island of the Republic of China in East Asia. Taiwan is located east of the Taiwan Strait, off the southeastern coast of mainland China...

     highlands. It differs from the type in having yellowish bark, odd-pinnate leaves that are also shorter on average at 45 to 60 cm (18–24 in) long with only 13–25 scythe-like leaflets. It is listed as endangered in the IUCN Red List
    IUCN Red List
    The IUCN Red List of Threatened Species , founded in 1948, is the world's most comprehensive inventory of the global conservation status of plant and animal species. The International Union for the Conservation of Nature and Natural Resources is the world's main authority on the conservation...

     of threatened species due to loss of habitat for building and industrial plantations.
  • A. altissima var. sutchuenensis, which differs in having red branchlets.

Distribution and habitat


A. altissima is native to northern and central China
China
China is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....

, Taiwan
Taiwan
Taiwan , also known as Formosa , is the largest island of the Republic of China in East Asia. Taiwan is located east of the Taiwan Strait, off the southeastern coast of mainland China...

 and northern Korea
Korea
Korea is a civilization and formerly unified nation currently divided into two states. Located on the Korean Peninsula, it borders China to the northwest, Russia to the northeast, and is separated from Japan to the east by the Korea Strait....

. In Taiwan it is present as var. takanai. In China it is native to every province
Province (China)
A province, in the context of Chinese government, is a translation of sheng , which is an administrative division. Together with municipalities, autonomous regions, and the special administrative regions, provinces make up the first level of administrative division in China...

 except Gansu
Gansu
' is a province located in the northwest of the People's Republic of China. It lies between Quinghai, Inner Mongolia, and the Huangtu plateaus, and borders Mongolia to the north and Xinjiang to the west. The Yellow River passes the southern part of the province. It has a population of nearly 31...

, Heilongjiang
Heilongjiang
' is a province of the People's Republic of China located in the northeastern part of the country. "Heilongjiang" literally means Black Dragon River, which is the Chinese name for the Amur. The one-character abbreviation is 黑...

, Hainan
Hainan
Hainan is the smallest province of the People's Republic of China . Although the province comprises some two hundred islands scattered among three archipelagos off the southern coast, all but three percent of its land mass is on Hainan Island , from which the province takes its name...

, Jilin
Jilin
' , is a province of the People's Republic of China located in the northeastern part of the country. Jilin borders North Korea and Russia to the east, Heilongjiang to the north, Liaoning to the south, and Inner Mongolia to the west...

, Ningxia
Ningxia
Ningxia , full name Ningxia Hui Autonomous Region , is a Hui autonomous region of the People's Republic of China, located on the northwest Loess highland, the Yellow River flows through a vast area of its land. The Great Wall of China runs along its northeastern boundary...

, Qinghai
Qinghai
' is a province of the People's Republic of China, named after Qinghai Lake. It borders Gansu on the northeast, the Xinjiang Autonomous Region on the northwest, Sichuan on the southeast, and Tibet Autonomous Region on the southwest.- History :Qinghai was only relatively recently made a province...

, Xinjiang
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China and also claimed by the territory of the Republic of China.-Names:Older English-language reference works often refer to the area as Chinese Turkestan, Sinkiang, East...

, and Tibet
Tibet
Tibet is a plateau region in Asia, north of the Himalayas. It is home to the indigenous Tibetan people, and to some other ethnic groups such as Monpas and Lhobas, and is now also inhabited by considerable numbers of Han Chinese people. Tibet is the highest region on earth, with an average...

.

The tree prefers moist and loamy soils, but is adaptable to a very wide range of soil conditions and pH
PH
pH is a measure of the acidity or basicity of a solution. It is defined as the cologarithm of the activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations...

 values. It is drought-hardy, but not tolerant of flooding. It also does not tolerate deep shade. In China it is often found in limestone
Limestone
Limestone is a sedimentary rock composed largely of the mineral calcite . The deposition of limestone strata is often a by-product and indicator of biological activity in the geologic record...

-rich areas. The tree of heaven is found within a wide range of climatic conditions. In its native range it is found at high altitudes in Taiwan as well as lower ones in mainland China. In the U.S. it is found in arid regions bordering the Great Plains
Great Plains
The Great Plains are the broad expanse of prairie and steppe which lie west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

, very wet regions in the southern Appalachians, and cold areas of the lower Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in Canada, to New Mexico, in the United States. The range's highest peak is Mount Elbert in Colorado at above sea level...

. Prolonged cold and snow cover cause dieback
Forest dieback
Forest dieback is a condition in trees or woody plants in which peripheral parts are killed, either by parasites or due to conditions like acid rain....

, though the trees re-sprout from the roots.

As an exotic plant


The earliest introductions of A. altissima to countries outside of its native range were to the southern areas of Korea
Korea
Korea is a civilization and formerly unified nation currently divided into two states. Located on the Korean Peninsula, it borders China to the northwest, Russia to the northeast, and is separated from Japan to the east by the Korea Strait....

 as well as to Japan
Japan
is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. It is possible that the tree is native to these areas, but it is generally agreed that the tree was a very early introduction. Within China itself it has also been naturalised beyond its native range in areas such as Qinghai
Qinghai
' is a province of the People's Republic of China, named after Qinghai Lake. It borders Gansu on the northeast, the Xinjiang Autonomous Region on the northwest, Sichuan on the southeast, and Tibet Autonomous Region on the southwest.- History :Qinghai was only relatively recently made a province...

, Ningxia
Ningxia
Ningxia , full name Ningxia Hui Autonomous Region , is a Hui autonomous region of the People's Republic of China, located on the northwest Loess highland, the Yellow River flows through a vast area of its land. The Great Wall of China runs along its northeastern boundary...

 and Xinjiang
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China and also claimed by the territory of the Republic of China.-Names:Older English-language reference works often refer to the area as Chinese Turkestan, Sinkiang, East...

.

In 1784, not long after Jussieu had sent seeds to England, some were forwarded to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 by William Hamilton, a gardener in Philadelphia. In both Europe and America it quickly became a favoured ornamental, especially as a street tree, and by 1840 it was available in most nurseries. The tree was separately brought to California
California
California is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...

 in the 1890s by Chinese immigrants who came during the California Gold Rush
California Gold Rush
The California Gold Rush began on January 24, 1848, when gold was discovered by James Wilson Marshall at Sutter's Mill, in Coloma, California. News of the discovery soon spread, resulting in some 300,000 men, women, and children coming to California from the rest of the United States and...

. It has escaped cultivation in all areas where it was introduced, but most extensively in the United States. It has naturalised across much of Europe, including Germany
Germany
Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...

, Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.3 million people in Central Europe. It borders both Germany and the Czech Republic to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west...

, Switzerland
Switzerland
Switzerland , officially the Swiss Confederation , is a federal republic consisting of 26 states named cantons, with Bern as the seat of the federal authorities...

, the Pannonian region (i.e. southeastern Europe from Italy
Italy
Italy , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...

 and Hungary
Hungary
Hungary , in English officially the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia. Its capital is Budapest. Hungary is a member of OECD, NATO, EU, V4 and is a Schengen state...

 south to Bosnia and Herzegovina
Bosnia and Herzegovina
Bosnia and Herzegovina Bosnia and Herzegovina Bosnia and Herzegovina ( or (Bosnian, Croatian, Serbian Latin: Bosna i Hercegovina; Serbian Cyrillic: Босна и Херцеговина) is a country in Southeast Europe, on the Balkan Peninsula...

) and most countries of the Mediterranean Basin
Mediterranean Basin
The Mediterranean Basin comprises the lands around and surrounded by the Mediterranean Sea. In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic...

. Ailanthus has also been introduced to Argentina
Argentina
Argentina, officially the Argentine Republic , is the second largest country in South America, constituted as a federation of 23 provinces and an autonomous city, Buenos Aires. It is the eighth largest country in the world by land area and the largest among Spanish-speaking nations, though Mexico,...

, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...

 (where it is a declared weed in New South Wales and Victoria), New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...

 (where it is listed under the National Pest Plant Accord
National Pest Plant Accord
The National Pest Plant Accord identifies pest plants that are prohibited from sale and commercial propagation and distribution across New Zealand....

 and is classed an "unwanted organism"), the Middle East and in some countries in South Asia such as Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan, is a country located at the crossroads of South Asia, the Middle East, and Central Asia...

.

In North America
North America
North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...

, A. altissima is present from Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. Most of its population of...

 in the east, west to southern Ontario
Ontario
Ontario is a province located in east-central Canada, the largest by population and second largest, after Quebec, in total area. Ontario is bordered by the Canadian provinces of Manitoba to the west and Quebec to the east, and 5 U.S...

, southwest to Iowa
Iowa
Iowa is a state located in the Midwestern region of the United States of America, an area often referred to as the "American Heartland." It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of...

, south to Texas
Texas
Texas is the second-largest U.S. state in both area and population, and the largest state in the contiguous United States.The name had wide usage among native Americans, meaning "friends" or "allies"...

, and east to the north of Florida
Florida
Florida is a state located in the southeastern region of the United States, bordering Alabama to the northwest and Georgia to the north. It was the 27th state admitted to the United States...

. On the west coast it is found from New Mexico
New Mexico
New Mexico is a state located in the southwestern region of the United States. Inhabited by Native American populations for many centuries, it has also been part of the Imperial Spanish viceroyalty of New Spain, part of Mexico, and a U.S. territory. Among U.S...

 west to California and north to Washington
Washington
Washington is a state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute. It was admitted to the Union as the...

. In the east of its range it grows most extensively in disturbed areas of cities, where it was long ago present as a planted street tree. It also grows along roads and railways. For example, a 2003 study in North Carolina
North Carolina
North Carolina is a state located on the Atlantic Seaboard in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties...

 found the tree of heaven was present on 1.7% of all highway and railroad edges in the state and had been expanding its range at the rate of 4.76% counties per year. Similarly, another study conducted in southwestern Virginia determined that the tree of heaven is thriving along approximately 30% of the state's interstate highway system length or mileage. It sometimes enters undisturbed areas as well and competes with native plants. In western North America it is most common in mountainous areas around old dwellings and abandoned mining operations.

Ecology



Ailanthus is an opportunistic plant that thrives in full sun and disturbed areas. It spreads aggressively both by seeds and vegetatively by root sprouts. It can re-sprout rapidly after being cut. It is considered a shade-intolerant tree and cannot compete in low-light situations, though it is sometimes found competing with hardwoods, but such competition rather indicates it was present at the time the stand was established. On the other hand, a study in an old-growth hemlock
Tsuga
Tsuga is a genus of conifers in the family Pinaceae. The common name hemlock is derived from a perceived similarity in the smell of the crushed foliage to that of the unrelated herb poison hemlock; see hemlock for other senses of the word. Unlike the herb, the species of Tsuga are not poisonous...

-hardwood forest in New York
New York
New York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...

 found that Ailanthus was capable of competing successfully with native trees in canopy gaps where only 2 to 15% of full sun was available. The same study characterised the tree as using a "gap-obligate" strategy in order to reach the forest canopy, meaning it grows rapidly during a very short period rather than growing slowly over a long period. It is a short lived tree in any location and rarely lives more than 50 years. Ailanthus is among the most pollution-tolerant of tree species, including sulfur dioxide
Sulfur dioxide
Sulfur dioxide is the chemical compound with the formula SO2. It is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide...

, which it absorbs in its leaves. It can withstand cement dust and fumes from coal tar operations, as well as resist ozone
Ozone
Ozone or trioxygen is a simple triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic O2. Ground-level ozone is an air pollutant with harmful effects on the respiratory systems of animals...

 exposure relatively well. Furthermore, high concentrations of mercury
Mercury (element)
Mercury , also called quicksilver or hydrargyrum , is a chemical element with the symbol Hg and atomic number 80...

 have been found built up in tissues of the plant.

Ailanthus has been used to re-vegetate areas where acid mine drainage has occurred and it has been shown to tolerate pH levels as low as 4.1 (approximately that of tomato juice). It can withstand very low phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks. Elemental phosphorus exists in two major forms - white phosphorus and red phosphorus...

 levels and high salinity levels. The drought-tolerance of the tree is strong due to its ability to effectively store water in its root system. It is frequently found in areas where few trees can survive. The roots are also aggressive enough to cause damage to subterranean sewers and pipes. Along highways it often forms dense thickets in which few other tree species are present, largely due to the toxins it produces to prevent competition.

Ailanthus produces an allelopathic chemical
Allelopathy
Allelopathy is a biological phenomenon that is characteristic of some plants, algae, bacteria, coral and fungi by which they produce certain biochemicals that influence the growth and development of other organisms. The biochemicals, called allelochemicals can have a beneficial or detrimental...

 called ailanthone, which inhibits the growth of other plants. The inhibitors are strongest in the bark and roots, but are also present in the leaves, wood and seeds of the plant. One study showed that a crude extract of the root bark inhibited 50% of a sample of garden cress
Garden cress
Garden cress is a fast-growing, edible herb that is botanically related to watercress and mustard, sharing their peppery, tangy flavor and aroma...

 (Lepidium sativum) seeds from germinating. The same study tested the extract as an herbicide on garden cress, redroot pigweed (Amaranthus retroflexus), velvetleaf
Velvetleaf
Velvetleaf is a common name used for plants with soft-haired leaves:* Abutilon theophrasti * Limnocharis flava Buchenau...

 (Abutilon theophrastii), yellow bristlegrass (Setaria glauca), barnyard grass (Echinochloa crusgalli), pea
Pea
A pea is most commonly the small spherical seed or the seed-pod of the legume Pisum sativum. Each pod contains several peas. Although it is botanically a fruit, it is treated as a vegetable in cooking...

 (Pisum sativum cv. Sugar Snap) and maize
Maize
Maize , is a herbaceous plant domesticated in Mesoamerica and subsequently spread throughout the American continents...

 (Zea mays cv.
Cultivar
A cultivar is a cultivated plant that has been selected and given a unique name because of desired characteristics; it is usually distinct from similar plants and when propagated it retains those characteristics....

 Silver Queen). It proved able to kill nearly 100% of seedlings with the exception of velvetleaf, which showed some resistance. Another experiment showed a water extract of the chemical was either lethal or highly damaging to 11 North American hardwood
Hardwood
The term 'hardwood' is used to describe wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood which...

s and 34 conifers, with the white ash (Fraxinus americana) being the only plant not adversely affected. The chemical does not, however, affect the tree of heaven's own seedlings, indicating that A. altissima has a defence mechanism to prevent autotoxicity
Autotoxicity
Autotoxicity is self-destruction of a species through the production of chemicals that escape into the environment and directly inhibit the growth of that species.This mechanism will result in reduced competition between members of the same species....

. Resistance in various plant species has been shown to increase with exposure. Populations without prior exposure to the chemicals are most susceptible to them. Seeds produced from exposed plants have also been shown to be more resistant than their unexposed counterparts.

The tree of heaven is a very rapidly growing tree, possibly the fastest growing tree in North America. Growth of one to two metres (3.3 to 6.6 ft) per year for the first four years is considered normal. Shade considerably hampers growth rates. Older trees, while growing much slower, still do so faster than other trees. Studies found that California
California
California is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...

n trees grew faster than their East Coast
East Coast of the United States
The East Coast of the United States, also known as the "Eastern Seaboard" or "Atlantic Seaboard", refers to the easternmost coastal states in the central and northern United States, which touch the Atlantic Ocean and stretch up to Canada...

 counterparts, and American trees in general grew faster than Chinese ones.

In northern Europe
Northern Europe
Northern Europe is the northern part or region of Europe. The United Nations defines Northern Europe as including the following countries and dependent regions:** ** ** Ireland** Svalbard and Jan Mayen** ** Channel Islands: and...

 the tree of heaven was not considered naturalised in cities until after the Second World War. This has been attributed to the tree's ability to colonise areas of rubble of destroyed buildings where most other plants would not grow. In addition, the warmer microclimate
Microclimate
A microclimate is a local atmospheric zone where the climate differs from the surrounding area. The term may refer to areas as small as a few square feet or as large as many square miles...

 in cities offers a more suitable habitat than the surrounding rural areas. For example, one study in Germany found the tree of heaven growing in 92% of densely populated areas of Berlin
Berlin
Berlin is the capital city and one of sixteen states of Germany. With a population of 3.4 million within its city limits, Berlin is Germany's largest city. It is the second most populous city and the eighth most populous urban area in the European Union...

, 25% of its suburbs and only 3% of areas outside the city altogether. In other areas of Europe this is not the case as climates are mild enough for the tree to flourish. It has colonised natural areas in Hungary
Hungary
Hungary , in English officially the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia. Its capital is Budapest. Hungary is a member of OECD, NATO, EU, V4 and is a Schengen state...

, for example, and is considered a threat to biodiversity at that country's Aggtelek National Park
Aggtelek National Park
Aggtelek National Park is a national park in Northern Hungary, in the Aggtelek karst region. It was founded in 1985. It contains 198.92 km² . It has been part of the UNESCO World Heritage since 1995...

.

Several species of Lepidoptera
Lepidoptera
Lepidoptera is an order of insects that includes moths and butterflies. It is one of the most speciose orders in the class Insecta, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

 utilise the leaves of ailanthus as food, including the Indian moon moth (Actias selene) and the common grass yellow
Eurema hecabe
The Large- or Common Grass Yellow is a small pierid butterfly species found in Asia. They are found flying close to the ground and are found in open grass and scrub habitats...

 (Eurema hecabe). In North America the tree is the host plant for the ailanthus webworm
Ailanthus webworm
The Ailanthus webworm, Atteva punctella, is an ermine moth now found commonly in the United States.The Ailanthus webworm is thought to be native to South Florida and the American tropics, habitat to its original larval host plant, the Paradise Tree...

 (Atteva punctella), though this ermine moth
Ermine moth
The family Yponomeutidae are known as the ermine moths, with several hundred species, most of them in the tropics. The larvae tend to form communal webs, and some are minor pests in agriculture, forestry, and horticulture. Some of the adults are very attractive...

 is native to Central
Central America
Managua
Guatemala City
San Salvador
San Pedro Sula
Panama City
San José, Costa Rica
Santa Ana, El Salvador
León
San Miguel|-|}...

 and South America
South America
South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...

 and originally used other members of the mostly tropical Simaroubaceae
Simaroubaceae
The Simaroubaceae is a small, mostly tropical, family in the order Sapindales. In recent decades it has been subject to much taxonomic debate, with several small families being split off....

 as its hosts. In its native range A. altissima is associated with at least 32 species of arthropods and 13 species of fungi.

Due to the tree of heaven's weedy habit, landowners and other organisations often resort to various methods of control in order to keep its populations in check. For example, the city of Basel
Basel
Basel is Switzerland's third most populous city . With 830000 inhabitants in the tri-national metropolitan area , Basel is Switzerland's second-largest urban area....

 in Switzerland has an eradication program for the tree. It can be very difficult to eradicate, however. Means of eradication can be physical, thermal, managerial, biological or chemical. A combination of several of these can be most effective, though they must of course be compatible. All have some positive and negative aspects, but the most effective regime is generally a mixture of chemical and physical control. It involves the application of foliar or basal herbicides in order to kill existing trees, while either hand pulling or mowing seedlings in order to prevent new growth.

Uses



In addition to its use as an ornamental plant, the tree of heaven is also used for its wood, medicinal properties, and as a host plant to feed silkworms of the moth Samia cynthia
Samia cynthia
The Ailanthus silkmoth is a saturniid moth, used to produce silk fabric but not as domesticated as the silkworm, Bombyx mori. The moth has very large wings of 113-125 mm, with a quarter-moon shaped spot on both the upper and lower wings, whitish and yellow stripes and brown background...

, which produces silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from cocoons made by the larvae of the mulberry silkworm Bombyx mori reared in captivity...

 that is stronger and cheaper than mulberry
Mulberry
Morus or Mulberry is a genus of 10–16 species of deciduous trees native to warm temperate and subtropical regions of Asia, Africa, Europe, and the Americas, with the majority of the species native to Asia....

 silk, although with inferior gloss and texture. It is also unable to take dye. This type of silk is known as "pongee
Pongee
Pongee is a soft thin woven cloth. In the early 1900s, pongee was an important export from China to the United States. Pongee is still woven in Silk by many mills across China. It is often called Habotai or Jap Silk. Generally it would vary in weight between 36 to about 50gm/sq m. In lighter...

" or "Shantung silk", the second name being derived from Shandong Province in China where this silk is often produced. Its production is particularly well known in the Yantai
Yantai
Yantai is a prefecture-level city in northeastern Shandong province, People's Republic of China. Located on the southern coast of the Bohai Sea and the eastern coast of the Laizhou Bay, Yantai borders the cities of Qingdao and Weihai to the southwest and east respectively.The largest fishing...

 region of that province. The moth has also been introduced in the United States.

The pale yellow, close-grained and satiny wood of ailanthus has been used in cabinet work. It is flexible and well suited to the manufacture of kitchen steamers
Steaming
Steaming is a method of cooking using steam. Steaming is considered a healthy cooking technique and capable of cooking almost all kinds of food.- Method :...

, which are important in Chinese cuisine
Chinese cuisine
Chinese cuisine originated in China and has become widespread in many other parts of the world — from Asia to the Americas, Australia, Western Europe and Southern Africa. In recent years, connoisseurs of Chinese cuisine have also sprouted in Eastern Europe and South Asia...

 for cooking mantou
Mantou
Mantou often referred to as humbao or Chinese steamed bun, is a kind of steamed bun originating in China. It is typically eaten as a staple in Northern parts of China where wheat rather than rice is grown. Made with milled wheat flour, water and leavening agents, they are similar in nutrition and...

, pastries and rice. Zhejiang Province in eastern China is most famous for producing these steamers. It is also considered a good source of firewood across much of its range as it moderately hard and heavy, yet readily available. There are problems with using the wood as lumber, however. Because the trees exhibit rapid growth for the first few years, the trunk has uneven texture between the inner and outer wood, which can cause the wood to twist or crack during drying. Techniques have been developed for drying the wood so as to prevent this cracking, allowing it to be commercially harvested. Although the live tree tends to have very flexible wood, the wood is quite hard once properly dried.

Cultivation


Tree of heaven is a popular ornamental tree in China and valued for its tolerance of difficult growing conditions. It was once very popular in cultivation in both Europe and North America, but this popularity dropped, especially in the United States, due to the disagreeable odour of its blossoms and the weediness of its habit. The problem of odour was previously avoided by only selling pistillate plants since only males produce the smell, but a higher seed production also results. Michael Dirr
Michael Dirr
Michael A. Dirr, Ph.D is a horticulturist and a professor of horticulture at the University of Georgia. He is an expert on woody plants.-Education and Experience:...

, a noted American horticulturalist and professor at the University of Georgia, reported meeting, in 1982, a grower who could not find any buyers. He further writes (his emphasis): In Europe, however, the tree is still used in the garden to some degree as its habit is generally not as invasive as it is in America. In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern Ireland is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning an archipelago including Great Britain, the northeastern part of Ireland, and many small islands...

 it is especially common in London
London
[]London is the capital of England and the United Kingdom. It has been a major settlement for two millennia, and the history of London goes back to its founding by the Romans, when it was named Londinium. London's core, the ancient City of London, the 'square mile', retains its medieval boundaries...

 squares, streets, and parks, though it is also frequently found in gardens of southern England and East Anglia
East Anglia
East Anglia is a traditional name for a region of eastern England, named after an ancient Anglo-Saxon kingdom, the Kingdom of the East Angles. The Angles took their name from their homeland Angeln, in northern Germany. East Anglia initially consisted of Norfolk and Suffolk, but upon the marriage of...

. It becomes rare in the north, occurring only infrequently in southern Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

. It is also rare in Ireland
Ireland
Ireland is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain...

. In Germany
Germany
Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...

 the tree is commonly planted in gardens. The tree has furthermore become unpopular in cultivation in the west due to the fact that it is short-lived and that the trunk soon becomes hollow, making trees more than two feet in diameter unstable in high winds.

A few cultivar
Cultivar
A cultivar is a cultivated plant that has been selected and given a unique name because of desired characteristics; it is usually distinct from similar plants and when propagated it retains those characteristics....

s exist, but they are not often sold outside of China and probably not at all in North America:
  • ‘Hongye’ – The name is Chinese and means "red leaves". As the name implies it has attractive vivid red foliage
  • ‘Thousand Leaders’
  • ‘Metro’ – A male cultivar with a tighter crown than usual and a less weedy habit
  • ‘Erythrocarpa’ – The fruits are a striking red
  • ‘Pendulifolia’ – Leaves are much longer and hang elegantly

Medicinal


Nearly every part of A. altissima has some application in Chinese traditional medicine. One of the oldest recipes, recorded in a work from 732 AD, is used for treating mental illness. It involved chopped root material, young boys' urine
Urine
Urine is a liquid waste product of the body secreted by the kidneys by a process of filtration from blood called urination and excreted through the urethra. Cellular metabolism generates numerous waste compounds, many rich in nitrogen, that require elimination from the bloodstream...

 and douchi
Douchi
Douchi, also called Chinese fermented black beans, is a flavoring most popular in the cuisine of China, and is used to make black bean sauce....

. After sitting for a day the liquid was strained out and given to the patient over the course of several days.

Another source from 684 AD, during the Tang dynasty
Tang Dynasty
The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...

 and recorded in Li Shizhen
Li Shizhen
Li Shizhen , courtesy name Dongbi , was one of the greatest physicians and pharmacologists in Chinese history. His major contribution to medicine was his forty-year work, which is found in his epic book the Bencao Gangmu...

's Compendium of Materia Medica
Compendium of Materia Medica
Bencao Gangmu , also known as Compendium of Materia Medica, is a Chinese materia medica work written by Li Shizhen in Ming Dynasty. It is a work epitomizing materia medica in Ming Dynasty. The Bencao Gangmu is regarded as the most complete and comprehensive medical book ever written in the history...

, states that when the leaves are taken internally, they make one incoherent and sleepy, while when used externally they can be effectively used to treat boils, abscess
Abscess
An abscess is a collection of pus that has accumulated in a cavity formed by the tissue on the basis of an infectious process or other foreign materials...

es and itches. Yet another recipe recorded by Li uses the leaves to treat baldness. This formula calls for young leaves of ailanthus, catalpa
Catalpa
Catalpa, also spelled Catawba, is a genus of flowering plants in the trumpet vine family, Bignoniaceae, native to warm temperate regions of North America, the Caribbean, and east Asia....

 and peach
Peach
The peach is known as a species of Prunus native to China that bears an edible juicy fruit also called a peach. It is a deciduous tree growing to 4–10 m tall, belonging to the subfamily Prunoideae of the family Rosaceae...

 tree to be crushed together and the resulting liquid applied to the scalp to stimulate hair growth.

The dried 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...

, however, is still an officinal
Officinal
Officinal is a term applied in medicine to drugs, plants and herbs, which are sold in a chemist or druggist shop, and to medical preparations of such drugs, et cetera, as are made in accordance with the prescriptions authorized by a pharmacopoeia. Not to be confused with the word "official"...

 drug and is listed in the modern Chinese materia medica
Materia medica
Materia medica is a Latin medical term for the body of collected knowledge about the therapeutic properties of any substance used for healing . In Latin, the term literally means "medical material/substance"...

 as chun bai pi , meaning "white bark of spring". Modern works treat it in detail, discussing chemical constituents, how to identify the product and its pharmaceutical uses. It is prepared by felling the tree in fall or spring, stripping the bark and then scraping off the hardest, outermost portion, which is then sun-dried, soaked in water, partially re-dried in a basket and finally cut into strips. The bark is said to have cooling and astringent
Astringent
An astringent substance is a chemical that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...

 properties and is primarily used to treat dysentery
Dysentery
Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the feces. If left untreated, dysentery can be fatal....

, intestinal hemorrhage, menorrhagia
Menorrhagia
Menorrhagia is an abnormally heavy and prolonged menstrual period at regular intervals. Causes may be due to abnormal blood clotting, disruption of normal hormonal regulation of periods or disorders of the endometrial lining of the uterus...

 and spermatorrhea
Spermatorrhea
Spermatorrhea is a condition of excessive, involuntary ejaculation.It is a recognized disorder in Traditional Chinese Medicine, in which certain patterns of involuntary ejaculation reflect problems with kidney qi....

. It is only prescribed in amounts between 4 and 10 grams, so as not to poison the patients. Li's Compendium has 18 recipes that call for the bark. Asian and European chemists have found some justification for its medical use as it contains a long list of active chemicals that include quassin
Quassin
Quassin is a white bitter, crystalline substance extracted from the quassia tree. It is the bitterest substance found in nature with a bitter threshold of 0.08 ppm and it is 50 times more bitter than quinine....

 and saponin
Saponin
Saponins are a class of chemical compounds, one of many secondary metabolites found in natural sources, with saponins found in particular abundance in various plant species...

, while ailanthone, the allelopathic chemical in the tree of heaven, is a known antimalarial agent. It is available in most shops dealing in Chinese traditional medicine. A tincture of the root-bark has been used successfully in treating cardiac palpitation, asthma
Asthma
Asthma is a predisposition to chronic inflammation of the lungs in which the airways are reversibly narrowed. Asthma affects 7% of the population of the United States, and 300 million worldwide...

 and epilepsy
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures...

.

The samara
Samara (fruit)
A samara is a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. A samara is a simple dry fruit and indehiscent . They are winged achenes...

s are also used in modern Chinese medicine under the name feng yan cao , meaning "herbal phoenix eye". They are used as a hemostatic agent, spermatorrhea
Spermatorrhea
Spermatorrhea is a condition of excessive, involuntary ejaculation.It is a recognized disorder in Traditional Chinese Medicine, in which certain patterns of involuntary ejaculation reflect problems with kidney qi....

 and for treating patients with blood in their feces or urine. It was clinically shown to be able to treat trichomoniasis
Trichomoniasis
Trichomoniasis, sometimes referred to as "trich", is a common cause of vaginitis. It is a sexually transmitted disease . It is caused by the single-celled protozoan parasite Trichomonas vaginalis...

, a vaginal infection caused by the protozoan Trichomonas vaginalis. In occident, an extract of the bark sold under the synonym A. glandulosa is sometimes used as an herbal remedy for various ailments including cancer
Cancer
Cancer is a class of diseases in which a group of cells display uncontrolled growth , invasion , and sometimes metastasis...

.

Anecdotal evidence suggests that the plant may be mildly toxic. The noxious odours have been associated with nausea and headaches, as well as with contact dermatitis
Contact dermatitis
Contact dermatitis or Irritant dermatitis is a term for a skin reaction resulting from exposure to allergens or irritants...

 reported in both humans and sheep, who also developed weakness and paralysis. It contains a quinone
Quinone
Quinones are "compounds having a fully conjugated cyclic dione structure, such as that of benzoquinones, derived from aromatic compounds by conversion of an even number of –CH= groups into –C– groups with any necessary rearrangement of double bonds ."Benzoquinone, sometimes referred to simply as...

 irritant, 2,6-dimethoxybenzoquinone, as well as active quassin
Quassin
Quassin is a white bitter, crystalline substance extracted from the quassia tree. It is the bitterest substance found in nature with a bitter threshold of 0.08 ppm and it is 50 times more bitter than quinine....

oids (ailanthone itself being one) which may account for these effects, but they have, however, proved difficult or impossible to reproduce in humans and goats. In one trial a tincture from the blossom and foliage caused nausea, vomiting and muscular relaxation.

China


In addition to the tree of heaven's various uses, it has also been a part of Chinese culture for many centuries and has more recently attained a similar status in the west. Within the oldest extant Chinese dictionary
Chinese dictionary
Chinese dictionaries date back over two millennia to the Eastern Zhou Dynasty, which is a significantly longer lexicographical history than any other language. There are hundreds of dictionaries for Chinese, and this article will introduce some of the most important...

, the Erya
Erya
The Erya is the oldest extant Chinese dictionary or Chinese encyclopedia. Bernhard Karlgren concluded that "the major part of its glosses must reasonably date from" the 3rd century BC....

, written in the 3rd century BC, the tree of heaven is mentioned second among a list of trees. It was mentioned again in a materia medica
Materia medica
Materia medica is a Latin medical term for the body of collected knowledge about the therapeutic properties of any substance used for healing . In Latin, the term literally means "medical material/substance"...

 compiled during the Tang dynasty
Tang Dynasty
The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...

 in 656 AD. Each work favoured a different character, however, and there is still some debate in the Chinese botanical community as to which character should be used. The current name, chouchun , means "stinking spring", and is a relatively new appellation. People living near the lower Yellow River
Yellow River
The Yellow River or Huang He / Hwang Ho is the second-longest river in China and the sixth-longest in the world at 5,464 kilometers . Originating in the Bayan Har Mountains in Qinghai Province in western China, it flows through nine provinces of China and empties into the Bohai Sea...

 know it by the name chunshu , meaning "spring tree". The name stems from the fact that A. altissima is one of the last trees to come out of dormancy, and as such its leaves coming out would indicate that winter was truly over.

In Chinese literature
Chinese literature
Chinese literature extends back thousands of years, from the earliest recorded dynastic court archives to the mature fictional novel that arose during the Ming Dynasty to entertain the masses of literate Chinese...

, ailanthus is often used for two rather extreme metaphors, with a mature tree representing a father and a stump being a spoiled child. This manifests itself occasionally when expressing best wishes to a friend's father and mother in a letter, where one can write "wishing your ailanthus and daylily
Daylily
Daylily is the common name of the species, hybrids and cultivars of the genus Hemerocallis . The flowers of these plants are highly diverse in colour and form, often resulting from hybridization by gardening enthusiasts. Thousands of registered cultivars are appreciated and studied by...

 are strong and happy", with ailanthus metaphorically referring to the father and daylily to the mother. Furthermore, one can scold a child by calling him a "good-for-nothing ailanthus stump sprout", meaning the child is irresponsible. This derives from the literature of Zhuangzi
Zhuangzi
Zhuangzi was an influential Chinese philosopher who lived around the 4th century BCE during the Warring States Period, corresponding to the Hundred Schools of Thought philosophical summit of Chinese thought...

, a Taoist philosopher, who referred to a tree that had developed from a sprout at the stump and was thus unsuitable for carpentry due to its irregular shape. Later scholars associated this tree with ailanthus and applied the metaphor to children who, like stump sprouts of the tree, will not develop into a worthwhile human being if they don't follow rules or traditions.

United States



The 1943 book A Tree Grows in Brooklyn by Betty Smith
Betty Smith
For other uses, see Betty Smith .Betty Smith, née Elisabeth Wehner , was an American author.-Biography:...

 uses the tree of heaven as its central metaphor, using it as an analogy for the ability to thrive in a difficult environment. At the time as well as now, ailanthus was common in neglected urban areas. She writes:

Ailanthus is also sometimes counter-nickname
Nickname
A nickname is a descriptive name given in place of or in addition to the official name of a person, place or thing. It can also be the familiar or truncated form of the proper name, which may sometimes be used simply for convenience A nickname (also spelled "nick name") is a descriptive name...

d "tree from hell" due to its prolific invasiveness and the difficulty in eradicating it. In certain parts of the United States, the species has been nicknamed the "ghetto palm" because of its propensity for growing in the inhospitable conditions of urban areas, or on abandoned and poorly maintained properties.

Until March 26, 2008, a -tall member of the species was a prominent "centerpiece" of the sculpture garden at the Noguchi Museum
Noguchi Museum
The Noguchi Museum, chartered as The Isamu Noguchi Foundation and Garden Museum, was designed and created by the Japanese-American sculptor Isamu Noguchi in 1985 to preserve and display his sculptures, architectural models, stage designs, drawings, and furniture designs. It is a two story museum...

 in the borough of Queens
Queens
Queens is the largest in area, the second-largest in population, and the easternmost of the Five Boroughs which form New York City. The Borough of Queens' boundaries are identical to those of the County of Queens , a subdivision of the State of New York in the Northeastern United States.Located on...

 in New York City
New York City
New York is the most populous city in the United States, and the center of the New York metropolitan area, which is among the most populous urban areas in the world. A leading global city, New York exerts a powerful influence over worldwide commerce, finance, culture, fashion and entertainment...

. The tree had been spared by the sculptor Isamu Noguchi
Isamu Noguchi
was a prominent Japanese American artist and landscape architect whose artistic career spanned six decades, from the 1920s onward. Known for his sculpture and public works, Noguchi also designed stage sets for various Martha Graham productions, and several mass-produced lamps and furniture pieces,...

 when in 1975 he bought the building which would become the museum and cleaned up its back lot. The tree was the only one he left in the yard, and the staff would eat lunch with Noguchi under it. "[I]n a sense, the sculpture garden was designed around the tree", said a former aide to Noguchi, Bonnie Rychlak, who later became the museum curator. By 2008, the old tree was found to be dying and in danger of crashing into the building, which was about to undergo a major renovation. The museum hired the Detroit Tree of Heaven Woodshop, an artists' collective, to use the wood to create benches, sculptures and other amenities in and around the building. The tree's rings were counted, revealing its age to be 75, and museum officials hoped it would regenerate from a sucker.

Europe


Ingo Vetter, a German artist and professor of fine arts at Umea University
Umeå University
Umeå University is a university in Umeå in the Midnorth of Sweden. The university was founded in 1965 and is the 5th oldest within Sweden's present borders....

 in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...

, was influenced by the idea of the "ghetto palm" and installed a living ailanthus tree taken from Detroit
Detroit
Detroit is the largest city in the U.S. state of Michigan and the seat of Wayne County. Detroit is a major port city on the Detroit River, in the Midwest region of the United States. Located north of Windsor, Ontario, Detroit is the only major U.S. city that looks south to Canada. It was founded...

 for an international art show called Shrinking Cities at the KW Institute of Contemporary Art in Berlin
Berlin
Berlin is the capital city and one of sixteen states of Germany. With a population of 3.4 million within its city limits, Berlin is Germany's largest city. It is the second most populous city and the eighth most populous urban area in the European Union...

in 2004.

External links