Family: Aceraceae (maples)

Status:

Description:
A small deciduous tree to about 8m high. Older bark is rough and grey-brown, but new shoots have a waxy white to blue coating. Leaves are compound, with 3-7 leaflets. Flowers are inconspicuous, and are followed by large clusters of drooping green winged seeds, or "keys".

Preferred habitat:
Widely planted as a fast-growing shade tree. Box elder is very invasive, particularly along river banks, although it can also be found growing in very dry sites.
Could behave similarly to willows along rivers, trapping sediment, causing erosion and depleting oxygen in the water by dumping large quantities of autumn leaves. Shades out native plants, creating ideal conditions for shade-loving weeds such as wandering jew.

Dispersal:
The winged keys can be blown long distances in the wind, or carried by water.

Look-alikes:
There are no similar natives.
The compound leaves distinguish box elder from other members of the maple family. Ashes (Fraxinus species) have similar leaves and keys. The desert ash, Fraxinus angustifolia has also become weedy in some areas, though it is not yet known to have naturalised on the south coast.

Control:
Hand pull seedlings. Cut and paint, stem injection, basal bark treatment in younger plants. Cut trees will re-sprout without painting.