Silver Maple

Scientific Name: Acer saccharinum. The genus Acer refers to maple trees, while saccharinum means sugary, alluding to the tree’s sweet sap.^1,12

Common Name: Silver maple. Silver refers to the pale, silvery undersides of the leaves. Similar common names are silverleaf maple and white maple. Additional names may include river maple, swamp maple, and water maple. With names like that, where do you think these trees like to grow?^1,12

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!

Average Height: 60-100 feet

Description: A fast-growing deciduous tree with opposite leaves that are light green on top and silvery to white on the underside. That’s the source of the tree’s common name—silver maple! The leaves measure up to 6” long and are divided into 5 pointed lobes with large teeth and deep sinuses. Twigs are chestnut brown with white lenticels and are said to have an unpleasant odor when broken. The bark is gray and smooth, becoming rougher and developing long, thin strips that begin to loosen with age, giving it a shaggy appearance. Trees are generally monoecious (having male and female flowers occurring together on the same tree). Both male and female flowers grow in clusters and are greenish to reddish with 4 sepals and no petals. Pollination occurs by wind, and the fertile female flowers develop into paired samaras about 1 ½–2 ½” long (those are the largest “helicopters” of any of our native maples!). The seeds mature in the summer to early fall and drop from the tree.^1,3,7,12,15

Bloom time: Feb – Apr

Notes: Acer saccharinum can hybridize with Acer rubrum (red maple) to become Acer x freemanii (Freeman’s maple). Natural occurrences of these hybrids are more commonly found in Wisconsin, Michigan, and Ontario. This hybrid is grown commercially for use in landscaping, where it is valued for retaining the fast-growth of the silver maple and the strength and more brilliant fall color of the red maple.¹⁴

Range: Locally common in the Ridge and Valley of Virginia, and in the Piedmont and Coastal Plain of Virginia north of the James River, though infrequent to the south of the river.⁵ Found from New Brunswick south to Florida, and as far west as North Dakota south to Oklahoma.⁶

Geology/Soil: Prefers moist soils containing loam, but also tolerates poor acidic soils. Soils may often be poorly drained, and range from moist to wet. These trees can also withstand temporary flooding. Used in landscaping as it can also adapt to drier soils and an urban environment.^1,7,12

Habitat: Most strongly associated with rivers, streams, and other wet areas including floodplain forests, riverbanks, swamps, and sand, gravel, and rocky bar woodlands. Sometimes found in other, more disturbed alluvial habitats where it may have escaped cultivation.^3,5

Flora associations: Found in floodplains with woody species such as boxelder (Acer negundo var. negundo), sycamore (Platanus occidentalis), green ash (Fraxinus pennsylvanica), black walnut (Juglans nigra), common hackberry (Celtis occidentalis), spicebush (Lindera benzoin), Virginia creeper (Parthenocissus quinquefolia), and poison ivy (Toxicodendron radicans). Herbaceous plants may include white snakeroot (Ageratina altissima), wood nettle (Laportea canadensis), wingstem (Verbesina alternifolia) and Virginia wild rye (Elymus virginicus).⁸

Fauna associations: With flowers that are wind pollinated, this tree has no insect pollinators, but sometimes honeybees will visit the male flower to collect pollen.⁷ Overall, maples (Acer spp.) are known to host around 274 species of moths and butterflies!⁹ These include some closely associated with Acer saccharinum such as two leaf blotch miner moths (Caloptilia bimaculatella and C. packardella), the maple leafblotch miner (Cameraria aceriella), and the showy rosy maple moth (Dryocampa rubicunda). Many plant bugs, beetles, aphids and other insects also feed on the leaves, sap, and wood of the tree such as a species of whitefly (Aleurochiton forbesii) that feeds on the underside of leaves and the painted maple aphid (Drepanaphis acerifoliae) that sucks sap from the tree.^7,10,13

Birds and mammals also have ties to the silver maple. Evening grosbeak (Coccothraustes vespertinus), pine grosbeak (Pinicola enucleator), and purple finch (Haemorhous purpureus) are a few birds that eat the seeds of the silver maple. Small mammals, especially squirrels and chipmunks, like to eat the seeds as well. When food is in short supply, squirrels will even eat the buds of the tree. Look for this behavior in late winter or early spring! Beavers use wood from Acer saccharinum as a building supply and eat it as well. Finally, older trees with cavities are great homes for cavity nesting birds and small mammals that live in dens.⁷

Human associations: Humans have found a wide variety of uses for Acer saccharinum—everything from medicine to food to a source of wood for making weapons and household items. Indigenous people from many nations use infusions made from the silver maple to treat ailments such as measles, hives, cramps, coughs, and diarrhea. The sap may be turned into sugar or used as an ingredient in beverages. Items made from the wood include arrows, bowls, furniture, and baskets. Acer saccharinum also has a history of use in landscaping.^1,11

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!!

1 “Acer Saccharinum – Plant Finder.” Www.missouribotanicalgarden.org, www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=275381. Accessed 12 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 Saccharinum L.” Vaplantatlas.org, 2024, www.vaplantatlas.org/index.php?do=plant&plant=806&search=Search. Accessed 12 Dec. 2024.

6 “NatureServe Explorer 2.0.” Explorer.natureserve.org, 6 Dec. 2024, explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.136917/Acer_saccharinum. Accessed 12 Dec. 2024.

7 “Silver Maple (Acer Saccharinum).” Illinoiswildflowers.info, 2019, www.illinoiswildflowers.info/trees/plants/silver_maple.htm. Accessed 12 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 Saccharinum.” Bugguide.net, 2024, bugguide.net/index.php?q=search&keys=acer+saccharinum&search=Search. Accessed 12 Dec. 2024.

11 “BRIT – Native American Ethnobotany Database.” Brit.org, 2024, naeb.brit.org/uses/search/?string=acer+saccharinum. Accessed 12 Dec. 2024.

12 “Acer Saccharinum (River Maple, Silverleaf Maple, Silver Maple, Swamp Maple, Water Maple, White Maple) | North Carolina Extension Gardener Plant Toolbox.” Plants.ces.ncsu.edu, plants.ces.ncsu.edu/plants/acer-saccharinum/. Accessed 12 Dec. 2024.

13 Wagner, David L. Caterpillars of Eastern North America : A Guide to Identification and Natural History. Princeton, N.J., Princeton University Press, 2005.

14 “Freeman Maple (Acer ×Freemanii) – Bplant.org.” Bplant.org, 2024, bplant.org/plant/8521. Accessed 14 Dec. 2024.

15 “Virginia Tech Dendrology Fact Sheet – Silver Maple.” Vt.edu, 2021, dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=5. Accessed 13 Dec. 2024.

Definitions:

Deciduous: Describes trees that lose their leaves.

Monecious: Describes a species for which the flowers are unisexual—either male or female—and both types of flowers are 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.

Sinus: A space between the lobes of a leaf.