tree-of-heaven

Ailanthus
Ailanthus altissima leaf and seeds
Scientific classification
Kingdom: Plantae (unranked): Angiosperms (unranked): Eudicots (unranked): Rosids Order: Sapindales Family: Simaroubaceae Genus: Ailanthus Desf.
Species
See text

Ailanthus (pronounced /əˈlænθəs/;^[1] derived from ailanto, an Ambonese word probably meaning "tree of the gods" or "tree of heaven") is a genus of trees belonging to the family Simaroubaceae, in the order Sapindales (formerly Rutales or Geraniales). The genus is native from east Asia south to northern Australasia.

They are fast-growing deciduous trees growing to 25-45 m tall, with spreading branches and large (40-100 cm) pinnate leaves with 15-41 long pointed leaflets, the terminal leaflet normally present, and the basal pairs of leaflets often lobed at their bases. The small yellow to greenish flowers are borne on branched panicles. They turn reddish later in the year and eventually brown. They stay on the tree for a long time; the male flowers have a strong odour. The odour tends to resemble the smell of strong cat urine or the spray of a male cat. Also, touching the leaves leaves an unpleasant smell on the hands. The fruit is a samara drawn out into a long wing with the seed in the middle. The wood is fine grained and satiny.

Species

The number of species is disputed, with some authorities accepting up to ten species, while others accept six or fewer. Species include:

• Ailanthus altissima (Tree of Heaven) – northern and central mainland China, Taiwan, arguably the best known species.
• Ailanthus excelsa – India and Sri Lanka
• Ailanthus integrifolia – New Guinea and Queensland, Australia
• Ailanthus malabarica – southeast Asia
• Ailanthus triphysa (White Siris) – northern and eastern Australia
• Ailanthus vilmoriniana (Downy Tree of Heaven) – southwest China

Ailanthus altissima flowers

This is considered an invasive species in North America. Ailanthus is capable of forming thick blankets of roots and heavy shade to the extent that native species are prevented from being able to reclaim an area that has been logged or deforested, as well as areas that have been heavily developed.^{[citation needed]}

In spite of being an invasive species on many places, this tree often grows where no others will. Thus it does not replace native species or more desirable trees and may only compete with weeds which have little value.^{[citation needed]}

A silk spinning moth, the Ailanthus silkmoth (Samia cynthia), lives on Ailanthus leaves, and yields a silk more durable and cheaper than mulberry silk, but inferior to it in fineness and gloss. This moth has been introduced to the eastern United States and is common near many towns; it is about 12 cm across, with angulated wings, and in colour olive brown, with white markings. Other Lepidoptera whose larvae feed on Ailanthus include Endoclita malabaricus.

References