Eastern Boxelder
Acer negundo var. negundo
Click or tap the section titles below to learn more about this species!
CLASSIFICATION: What’s in a name?
Scientific Name: Acer negundo var. negundo. The genus Acer refers to maple trees. The species name negundo originally comes from Sanskrit and was first used as the species name for the Chinese chaste tree (Vitex negundo), a tree found in Africa and Asia that has leaves similar to those of Acer negundo var. negundo.1
Common Name: Eastern boxelder. Other common names include boxelder and ashleaf maple. Did you notice the references to a couple of other trees in these common names? Similarities between the leaves of elder (Sambucus spp.) and ash (Fraxinus spp.) trees with those of Acer negundo var. negundo have led to their inclusion in the common names for this species of maple.1
Family: Sapindaceae (Soapberry Family). The roughly 1,900 species in this family are concentrated in the tropical regions, with some species in the temperate region. The majority are woody plants (trees, shrubs, and vines) with alternate, pinnately compound leaves. Flowers usually have 4–5 petals and are mostly insect pollinated. The fruits may be berries, dry capsules, or samaras (winged “helicopters” like those on maple trees!). Species in this family that you may be familiar with include maples (Acer spp.), buckeyes (Aesculus spp.), soapberry (Sapindus spp.), and commercially grown fruits such as lychee (Litchi chienensis).2,3,4
In the past 15 years, scientists have debated whether some of the plants included in this family should actually be put into families of their own. Some resources will have maples in the maple family (Aceraceae) but recent work supports including maples in Sapindaceae.4 As our knowledge of the natural world evolves, scientists often make changes to classifications—including how plants are divided into families!
IDENTIFICATION: What does it look like?
Average Height: 30-50 feet
Description: A fast-growing deciduous tree that may have multiple trunks. The light to medium green compound leaves are arranged opposite each other and are usually divided into 3 leaflets, but may sometimes have 5, 7, or rarely, 9 leaflets. Leaflets measure 2–5” long, and are ovate and irregularly toothed. Twigs and young bark are green to purplish green with pale lenticels (those small, raised bumps on the surface of the bark), while more mature bark is gray to brown with furrows. Boxelder is dioecious, meaning each tree has only male or female flowers (like green ash and common persimmon!). Both male and female flowers form dangling clusters, and pollination occurs by wind. Male and female flowers have no petals and 5 sepals. Fertile female flowers develop into paired samaras about 1–1 ½” long (it’s a maple—these are its “helicopters!”). Samaras frequently remain on the tree throughout winter.1,3,7
Bloom time: Mar – May
Notes: Acer negundo var. negundo is unusual among maples, having leaves with 3–9 leaflets. This structure means that boxelder may sometimes be confused with poison ivy (Toxicodendron radicans). Although they both appear to have “leaves of three,” poison ivy differs from boxelder in several ways: leaves are borne alternately along the stem (instead of opposite), leaves always have 3 leaflets (instead of 3–7), and the plant has a vining habit (instead of growing as a tree).3,7
LOCATION: Where is it at home?
Range: Found throughout Virginia, but most abundant in floodplains located in the mountains and Piedmont.5 Ranges from Maine west to North Dakota and Manitoba, and south to Texas and Florida, with a few additional western states.6
Geology/Soil: Prefers moist to wet soils and can tolerate up to a month of flooding, although it can sometimes be found in poor, dry soil. Grows it many soil types including sand, clay, loam and gravelly soil.1,7
Habitat: Most strongly associated with rivers, streams, and other wet areas including floodplain forests, riverbanks, swamps, old alluvial fields, and disturbed areas.3,5,6
CONNECTIONS: What are its relationships to other plants, animals, and humans?
Flora associations: Found in floodplains with trees such as silver maple (Acer saccharinum), sycamore (Platanus occidentalis), green ash (Fraxinus pennsylvanica), black walnut (Juglans nigra), and common hackberry (Celtis occidentalis). The understory may include spicebush (Lindera benzoin), pawpaw (Asimina triloba), poison ivy (Toxicodendron radicans), white snakeroot (Ageratina altissima), wood nettle (Laportea canadensis), and Virginia wild rye (Elymus virginicus), or in slightly higher, nutrient-rich areas, many common spring ephemerals like Virginia bluebell (Mertensia virginica).8
Fauna associations: With flowers that are wind pollinated, this tree has no insect pollinators, but there are still plenty of insects associated with it! The one that you likely know best is the orange and black eastern boxelder bug (Boisea trivittata), which may try to overwinter in your home! Other species that feed on boxelder include shimmering gold adoxophyes moth (Adoxophyes negundana), boxelder ball midge (Contarinia negundinis), boxelder psyllid (Cacopsylla negundinis), and the boxelder twig borer moth (Proteoteras willingana). Notice how many of the species names reference negundo!7,10 Overall, maples (Acer spp.) are known to host around 274 species of moths and butterflies!9
Birds and mammals also have ties to the boxelder tree. Evening grosbeak (Coccothraustes vespertinus), pine grosbeak (Pinicola enucleator), and purple finch (Haemorhous purpureus) all eat the seeds of the boxelder. As a host plant for many moths, butterflies, and other insects, the boxelder also is a great place for insect-loving birds like warblers to grab a meal! The tree provides cover and nesting sites for a number of birds, as well as roosting sites for several species of bats. In the winter, white-tailed deer and American moose will eat the twigs and branches.7
Human associations: Over time, humans have found a variety of uses for Acer negundo var. negundo. A widespread use by Indigenous people from many nations is to turn the sap into sugar. The wood is used to create bowls, pipe stems, drums, and prayer sticks, or is burned for fuel or used during ceremonies. The Dakota, Omaha, and Sioux people use charcoal made from boxelder to create tattoos. An infusion of the bark may also be used as an emetic.11
We want these plants to thrive and for everyone who gets to visit the park to enjoy them, so remember – don’t pick flowers or other parts of the plant!!
Bibliography & Definitions
1 “Acer Negundo – Plant Finder.” Www.missouribotanicalgarden.org, www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a841. Accessed 10 Dec. 2024.
2 Porter, Duncan M., and Kenneth J. Sytsma. “Sapindaceae | Plant Family | Britannica.” Www.britannica.com, www.britannica.com/plant/Sapindaceae. Accessed 11 Dec. 2024.
3 Weakley, A.S., J.C. Ludwig, and J.F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project, Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press, pp.923-927.
4 Weakley, A.S, and SE Flora Team. “Sapindaceae (Soapberry Family) – FSUS.” Unc.edu, 2024, fsus.ncbg.unc.edu/main.php?pg=show-taxon.php&exactmatch=yes&plantname=Sapindaceae. Accessed 16 Jan. 2025.
5 “Digital Atlas of the Virginia Flora | Acer Negundo L. Var. Negundo.” Vaplantatlas.org, 2024, www.vaplantatlas.org/index.php?do=plant&plant=810&search=Search. Accessed 11 Dec. 2024.
6 “NatureServe Explorer 2.0.” Natureserve.org, 2024, explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.154814/Acer_negundo_var_negundo. Accessed 11 Dec. 2024.
7 “Box Elder (Acer Negundo).” Illinoiswildflowers.info, 2024, www.illinoiswildflowers.info/trees/plants/box_elder.htm. Accessed 11 Dec. 2024.
8 “Piedmont / Mountain Floodplain Forests and Swamps.” Virginia.gov, 2021, www.dcr.virginia.gov/natural-heritage/natural-communities/ncpa5. Accessed 11 Dec. 2024.
9 “Specify Your Location – Native Plants Finder – Boxelder.” Nwf.org, 2015, nativeplantfinder.nwf.org/Plants/16. Accessed 11 Dec. 2024.
10 “Search – Acer Negundo.” Bugguide.net, 2024, bugguide.net/index.php?q=search&keys=acer+negundo&search=Search. Accessed 11 Dec. 2024.
11 “BRIT – Native American Ethnobotany Database.” Brit.org, 2024, naeb.brit.org/uses/search/?string=acer+negundo. Accessed 12 Dec. 2024.
Definitions:
Compound leaf: A leaf that is divided into several leaflike divisions, called leaflets. A compound leaf may appear to be several leaves, but the whole will come from a single bud.
Deciduous: Describes trees that lose their leaves.
Dioecious: Describes a species for which the flowers are unisexual—either male or female—and only one type of flower is present on an individual tree.
Lenticel: A lens-shaped area on the surface of a stem or root that is slightly raised.
Samara: A dry, winged fruit dispersed by the wind. The “helicopters” from maple trees are a good example of a samara.