Box Elder
Acer negundo
The Box Elder (Acer negundo) is a fast-growing, highly adaptable deciduous tree that breaks nearly every rule of what a maple "should" look like. Unlike its elegant cousins with palmately lobed leaves, the Box Elder bears compound leaves with 3 to 7 leaflets, more closely resembling an ash or elderberry — hence its alternative common name, Ash-leaved Maple. It is one of the most widespread and weediest maple species in North America.
• Typically reaches 10 to 20 meters tall with a short, often crooked trunk and spreading crown
• The only common North American maple with compound (pinnate) leaves
• Dioecious — individual trees are either male or female
• Extremely fast-growing, often weedy and short-lived (50 to 75 years)
• One of the most drought-tolerant maples
Taxonomie
• Extends from southern Alberta and Saskatchewan south through the Great Plains and Rocky Mountains to northern Mexico
• Also native to the eastern United States from New England to Florida
• Found from sea level to approximately 2,000 meters elevation in mountainous areas
• Several subspecies exist across its range, including varieties adapted to the Great Plains, the Southwest, and the Pacific coast
• Also native to parts of Central America (Guatemala)
• Described by Linnaeus in 1753
• Has become naturalized in Europe, Asia, and Australia, where it is often considered invasive
Bark:
• Gray-brown to light brown, developing narrow ridges and furrows with age
• Young bark is smooth and greenish-gray
Leaves:
• Opposite, pinnately compound with 3 to 7 (sometimes 9) leaflets — highly unusual for a maple
• Each leaflet 5 to 10 cm long, lanceolate to ovate, with coarsely toothed margins
• Light green, turning yellow in fall
Fruit:
• Paired samaras in dense, hanging clusters, 2 to 3 cm long
• Wings at an acute angle, often persisting through winter
• Female trees produce abundant, conspicuous seed clusters
Size:
• Typically 10 to 20 meters tall and 30 to 50 cm trunk diameter
• Short-lived, rarely exceeding 75 years
• A pioneer species that rapidly colonizes disturbed sites, floodplains, and forest edges
• Highly tolerant of drought, flooding, and poor soils — among the most adaptable maples
• Wind-pollinated flowers appear in early spring before the leaves
• Seeds are an important winter food source for songbirds, particularly grosbeaks and finches
• Deer and rabbits browse heavily on young shoots and seedlings
• Provides nesting habitat for birds and cavity-dwelling wildlife
• Commonly forms thickets along streams and in disturbed areas
• Roots help stabilize streambanks and control erosion
• Often considered weedy or invasive in cultivated landscapes
• One of the most common and widespread tree species in North America
• Populations are stable and increasing in many areas
• Considered invasive in parts of Europe, eastern Asia, and Australia where it has been introduced
• Not subject to any conservation concern in its native range
• Hardy in USDA zones 2 to 9 — among the hardiest of all maples
• Adaptable to virtually any soil type including heavy clay, sandy, alkaline, and saline soils
• Highly drought-tolerant once established
• Also tolerates seasonal flooding and compacted soils
• Full sun to partial shade
• Very fast growth rate of 60 to 120 cm per year in ideal conditions
• Short-lived and prone to breakage in storms due to weak wood
• Female trees produce copious seeds and can be messy; male trees are preferred for landscapes
• Generally not recommended as a landscape specimen due to its weedy nature and weak structure
Wood products:
• Soft, light, pale wood used for crates, boxes, pallets, and inexpensive furniture
• Historically used by Native American peoples for making bowls, utensils, and tools
• Sometimes used for pulpwood and charcoal production
Ornamental:
• Variegated and golden-leaved cultivars (such as 'Flamingo' and 'Auratum') are grown as ornamental shrubs
• Occasionally planted for rapid shade in harsh climates where few other trees survive
Ecological:
• Valuable for riparian restoration and erosion control
• Provides quick cover on disturbed sites
• Important wildlife food source through its abundant seeds
Anecdote
The Box Elder is the only North American maple with compound leaves, making it look more like an ash tree than a maple — which is why it is sometimes called the "Ash-leaved Maple." Despite its reputation as a weed tree, it has been cultivated in European gardens since 1688, and several colorful variegated cultivars are prized by gardeners.
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