Ailanthus altissima
Ailanthus excelsa
Ailanthus giraldii
Ailanthus malabarica
Ailanthus triphysa
Ailanthus vilmoriniana

Ailanthus (derived from ailanto, an Amboine word probably meaning "tree of the gods" or "tree of heaven") is a genus of 6-10 species of trees belonging to the family Simaroubaceae , in the order Rutales . Sometimes the family is placed in the Geraniales. The genus is native from east Asia south to northern Australasia.

The best known species, A. altissima, English name Tree of heaven, is a native of northern China. It is a quick-growing deciduous tree to 25-35m tall, with spreading branches and large (40-80 cm) pinnate leaves with 15-35 long pointed leaflets, the terminal leaflet normally present, and the basal pairs of leaflets often lobed at their bases. The small greenish flowers are borne on branched panicles; and the male ones are characterized by having a disgusting odour. The fruits are free in clusters, and each is drawn out into a long wing with the seed in the middle. The wood is fine grained and satiny.

The tree was introduced into England in 1751 and is a favourite in parks and gardens. It has also been introduced into North America. This tree has the reputation as being the most urban-tolerant of any temperate-zone tree in the world, growing in places where most weeds even refuse to grow. Where the climate is sufficiently similar to that of its homeland, as in much of the east and south of both the United States and Europe, it has proved to be a serious problem invasive species, causing major problems both in urban areas (where the roots of saplings that germinate close to buildings cause damage to foundations), and in rural areas (where it displaces native species from the environment). A consequent popular nickname for the species is Tree from hell.

A. altissima is sometimes also known as A. glandulosa or A. glanduosa. Under this name, an extract of the bark is sometimes touted as an herbal homeopathic remedy for various ailments. However, taken in large doses, the bark extract is highly toxic.

Other species of Ailanthus include A. triphysa, an Australian tree; A. vilmoriniana and A. giraldii in south and west China, A. malabarica in southeast Asia, and A. excelsa, common in India.

A silk spinning moth, the Ailanthus moth (Samia cynthia), lives on its 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.

External links

• Ailanthus and Staghorn Sumac, from The Monday Garden.

Section Eclectic herbal information

• Ailanthus glandulosa (Tree of Heaven) King's American Dispensatory @ Henriette's Herbal
• Tree of Heaven (Ailanthus glandulosa) Mrs. Grieve's "A Modern Herbal" @ Botanical.com

Section Homeopathic information

• Ailanthus glandulosa (ail.) "Kent's Lectures on Homeopathic Materia Medica" by Dr Robert Séror
• Ailanthus "A Primer of Materia Medica for practitioners of Homœopathy" by Timothy Allen