Species list


Ailanthus altissima

Tree of heaven

Tree of heaven, ailanthus (Eng); árbol del cielo, ailanto (Spa); ailant (Cat); ailantoa (Baq); ailanto, árbore do ceo (Glg); ailanto, ailanto-da-China (Por).


DID YOU KNOW...? Although in the botanical description of the species it says: "Tree of heaven, as, because of its height, it seems to launch itself against the sky", it is actually named for its rapid growth.


Tree reaching 30 m in height, with smooth, greyish bark, whose trunk is reminiscent of an elephant's leg. The leaves are very large, up to almost a metre in length, deciduous, alternate and compound with an odd number of leaflets (odd-pinnate), which give it a feathery appearance. The margin of the leaflets is irregular, often with angular lobes at the base. The leaflets also smell bad when crushed, which is why in some languages is known as the "foul smelling tree", or malhuele in Spanish. Male and female flowers usually appear on different plants, so there are separate male trees and female trees. They are greenish, with 5 hairy petals that also have a disagreeable scent, and which are arranged in complex hanging clusters 10-20 cm in length. The fruits are dry and consist of a seed the size of a lentil surrounded by a long membranous wing (samara), which aids their dispersal by the wind. When they are ripe they dry out and twist a little.


This tree needs a lot of light, but is otherwise an undemanding plant that thrives in all soil types, even in dry and stony or sandy areas, and withstands adverse environmental conditions such as extreme temperatures, summer drought and pollution. It has no trouble becoming established in the wild and is very competitive as it germinates, roots and sprouts again very easily. It grows quickly and can produce up to 350,000 seeds per year when adult. It can also reproduce by means of suckers. Generally, this tree becomes established in inhabited or disturbed areas on the midslopes, or medianías (zones between 600 and 1500 m above sea level), like abandoned fields, embankments and ditches, although it also invades areas of natural vegetation along roads and paths, often helped by the wind.


This tree native to Southeast Asia has naturalised in many parts of the world. During the 20th century it was introduced into the Canary Islands as an ornamental. It has become established in the wild in Gran Canaria and Tenerife, where it grows in the Parque Rural de Teno, a protected natural area. On the other hand, according to Flora y fauna terrestre invasora en la Macaronesia. TOP 100 en Azores, Madeira y Canarias, it may also have naturalised in Fuerteventura and, according to the botanist Maria Leticia Rodriguez Navarro (November 2014),several wild specimens have been seen in the Breña Alta municipality in La Palma. Included in the Atlas of invasive alien plants of Spain.