Acer negundo (Box Elder)

 

Acer negundo is a species of maple native to North America. Box elder, boxelder maple, ash-leaved maple, and maple ash are its most common names in the United States; in Britain and Ireland it is also known as ashleaf maple.

 

Acer negundo is a small, usually fast-growing and fairly short-lived tree that grows up to 10–25 metres (33–82 ft) tall, with a trunk diameter of 30–50 centimetres (12–20 in), rarely up to 1 metre (3.3 ft) diameter. It often has several trunks and can form impenetrable thickets.

 

The shoots are green, often with a whitish to pink or violet waxy coating when young. Branches are smooth, somewhat brittle, and tend to retain a fresh green colour rather than forming a bark of dead, protective tissue. The bark on its trunks is pale gray or light brown, deeply cleft into broad ridges, and scaly.

 

Although its light, close-grained, soft wood is considered undesirable for most uses, this tree has been considered as a commercial source of wood fiber, for use in fiberboard.

There is some commercial use of the tree for various decorative applications, such as turned items (bowls, stem-ware, pens). Primarily burl wood and injured wood, where the primary reason is this wood's reaction to injury, where the injured wood develops a red stain

 

The flowers are small and appear in early spring on drooping racemes 10–20 centimetres (3.9–7.9 in) long. The fruits are paired samaras, each seed slender, 1–2 centimetres (0.39–0.79 in) long, with a 2–3 centimetres (0.79–1.18 in) incurved wing; they drop in autumn or they may persist through winter. Seeds are usually both prolific and fertile.

Unlike most other maples, A. negundo is fully dioecious and both a "male" and "female" tree are needed for either to reproduce.