Box Elder

Box Elder — Acer negundo is a species of maple native to North America. Boxelder, Boxelder Maple, and Maple Ash are its most common names in the United States. Other English names such as Ash Maple, Ash-leaf Maple, Black Ash, California Boxelder, Cutleaf Maple, Cut-leaved Maple, Negundo Maple, Red River Maple, Stinking Ash, Sugar Ash, Three-leaved Maple, and Western Boxelder. In Canada it is known as Manitoba Maple. In Russia it is called American Maple.

It is a small, usually fast-growing and fairly short-lived tree that grows up to 10-25 m tall, with a trunk diameter of 30-50 cm, rarely up to 1 m 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.

Unlike most other maples (which usually have palmate leaves), it has pinnate leaves that have three to seven leaflets (usually three). Although some other maples (such as A. griseum, Acer mandshuricum and the closely-related A. cissifolium) have trifoliate leaves, only A. negundo regularly displays more than three leaflets.

The leaflets are about 5-10 cm long and 3-7 cm wide with slightly serrate margins. Leafs have a translucent light green colour and turn yellow in fall.

The flowers are small and appear in early spring on drooping racemes 10-20 cm long. The seeds are paired samaras, each seed slender, 1-2 cm long, with a 2-3 cm 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.