Tree of heaven
From Freepedia
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| Image:Ailanthus altissima4.jpg Leaves and flowers | ||||||||||||||
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| Ailanthus altissima (Mill.) Swingle |
The Tree of Heaven (Ailanthus altissima) is a member of the quassia family, Simaroubaceae, native to northeast and central China. It is a deciduous tree, which grows rapidly and can reach up to 25 m tall, rarely 35 m, with a trunk up to 1 m diameter, rarely 1.5 m diameter. The common name is a direct translation of its Indonesian name ailanto; it is also sometimes counter-nicknamed "Tree from Hell". It is also sometimes referred to as a "Ghetto Palm" because of its propensity for growing in poor neighborhoods where there are often abandoned or poorly kept properties.
The bark of the tree is smooth and light grey, while the stems are reddish or chestnut. Its large, compound leaves are arranged alternately on the stem, and can be 30-60 cm long (occasionally up to 1 m long on vigorous young sprouts) and contain 11-33 leaflets, occasionally up to 41 leaflets. Each leaflet has one to three teeth on each side, close to the base. This helps distinguish it from sumacs (Rhus spp.).
The flowers are small, yellow-green to reddish, produced in late spring to mid summer in panicles up to 30 cm long. It is dioecious, with trees being either all male or all female. The seed is 5 mm diameter, encapsulated in a samara 4 cm long and 1 cm broad; the samara is twisted, making it spin as it falls, assisting wind dispersal. Female trees can produce more than 300,000 seeds in a year. All parts of this tree produce an unpleasant odour.
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Cultivation and uses
Tree of Heaven is a popular ornamental tree in China, valued for its tolerance of difficult growing conditions, and its uses in Chinese traditional medicine. The bark is used to treat dysentery and other bowel ailments. A tincture of the root-bark has been used successfully in cardiac palpitation, asthma and epilepsy. The leaves are also used to feed silkworms of the moth Samia cynthia, which produces silk that is stronger and cheaper than mulberry silk, although with inferior gloss and texture.
It was first introduced to Europe (France and England) by a French Jesuit priest returning from Nanking in 1751, and the United States by a gardener in Philadelphia in 1784. By 1840, it was available in many nurseries. As a second point of entry, the tree was brought to California by Chinese immigrants who worked the gold mines. To this day many abandoned mines have large colonies of Ailanthus altissima.
Control
Tree of Heaven has become a problem invasive species in many areas, including 42 U.S. states from Maine to Florida to California, and most countries in central and southern Europe from Bulgaria west to Portugal and north to Germany. The book "A Tree Grows in Brooklyn" by Betty Smith referred to the Tree of Heaven. It is a notoriously prolific plant that can thrive in very difficult conditions.
It reproduces by both sexual (from seeds) and asexual (from root suckers) means. Because of its aggressive spread and vigorous growth, it has become problem in many areas, out-competing native species. It also produces toxins which inhibit the growth of other trees. The roots can damage sewers and housing foundations.
Diligence is the key to controlling Ailanthus altissima. Cutting alone is not sufficient to kill the tree, as it resprouts quickly and abundantly. Also, cutting stimulates the roots to produce suckers. Young seedlings should be pulled out completely, including the roots. Vigilent cutting and recutting may be able to kill a small tree by destroying its energy reserves.
Cutting and spraying is a recommended method. Since separate male and female trees exist, efforts should focus on the female, seed-producing trees to first slow the spread of new seedlings.
Similar Species
Staghorn Sumac Rhus typhina is a true sumac that can be identified by its red and slightly hairy stems, as well as leaves that are serrated, instead of having the base teeth of A. altissima. Smooth Sumac Rhus glabra, also lacks the base teeth of A. altissima.
External links
- Alien Plant Group – Ailanthus altissima
- Introduction of Non-native plants to Massachusetts
- Botanical.com: Tree of Heaven
- National Park Service fact sheet
