The honey locust was named for the botanist Gottlieb Glcditsch and for its three-branched, 5 to 15-centimetre-long spines, which grow on the trunk and branches. It is a native of eastern North America, where it is found on moist, rich soils from Texas, northward to the 43rd parallel. It can tolerate drier situations, and is planted in tree belts in the prairies.

It is scattered. throughout woods at elevations ranging from hill country to heights of 1500 metres, growing mainly in the mountains. Preferring a cool, humid climate and a well- drained soil, it is found predominantly in mountain valleys, scree woods and alongside mountain streams. It reaches a height of 30 to 35 metres and a trunk diameter of 150 centimetres, living for several hundred years. The bark is grey-brown, and peels off in small flat plates; the upright buds are green, the scales edged with brown. The long-stalked leaves are opposite, and the greenish flowers appear in April and May.

The honey locust is a light-demanding tree and stands up well to cutting-back. It is found in parks, and sometimes in the vicinity of country dwellings, where it is used as a thorny hedge. The wood, which is hard with reddish brown heartwood, is highly prized. The unripe pods are a favourite food of livestock and the dye they yield is used in colouring fabrics.

The tree of heaven is native to the southern half of China, and in 1751 was introduced into Europe, where it is now grown in the cities and parks in the western, central and southern areas. Thriving best in a mild climate, it grows well in warm lowland areas, particularly in cities, where it has great powers of natural regeneration on clumps and demolished sites.

The twigs are green, covered with a bluish bloom when young. The trunk is often crooked, and the bark is divided into ridges by shallow fissures. Unlike all other European maples, it has compound odd-pinnate leaves. The tiny greenish flowers are clustered in pendent racemes and appear as the leaves unfold. The fruit, which matures in autumn, appears also in pendent clusters.

In its native environment, the Box-elder grows mostly in river valleys, and near lakes, on moist soils. However, it appears to be very adaptable, and also grows fairly well in dry situations. It is of little importance in European forestry, because of its brief life span and poor quality wood, but is often planted as an ornamental. Its rapid growth in youth makes it a good tree for providing quick screens in parks and gardens. Also very ornamental are the yellow and silver variegated leaved forms which are more frequently seen in gardens.