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Silver maple is a relatively large tree, commonly reaching a height of 15–25 m, often with multiple stems. Bark of young trees and branches is smooth and light grey; mature trees develop long ridges or scales. The leaves are palmate, 8–16 cm long and 6–12 cm broad, with deep angular notches between the five lobes. The 5–12 cm long, slender stalks of the leaves mean that even a light breeze can produce a striking effect as the silver undersides of the leaves are exposed. The flowers are in small panicles, produced before the leaves in early spring, with the seeds maturing in early summer. The fruits are paired samaras (nutlets with stiff fibrous wings), with wings about 3–5 cm long. Although the wings provide for some aerial transport, the heavy seeds may also be transported by water.
Silver maple is fast-growing, tolerates a wide variety of soils and urban conditions, and is easy to propagate and transplant, so it has been widely used as an ornamental and shade tree. It is also commonly cultivated outside its native range, showing tolerance of a wide range of climates, growing successfully as far north as central Norway and south to Orlando, Florida. It can thrive in a Mediterranean climate and is grown in temperate parts of the Southern Hemisphere. However, urban plantings have declined in recent years because its brittle branches break off easily in storms (Barnes and Wagner 2004), and the shallow, fibrous roots easily invade septic fields and old drain pipes, and can crack sidewalks and foundations.
Silver maple is closely related to (and sometimes confused with) red maple (Acer rubrum). The leaves can be distinguished by the longer, more deeply dissected lobes (with the sides of the middle lobe diverging) and the silvery underside; the samaras have larger wings that diverge at a wider angle. In natural areas, silver maple is generally restricted to river floodplains, streambanks, and deciduous swamps, but although it may occur in moist woods, it is not found in the drier uplands where red maple increasingly occurs. The two species can hybridize in natural wetlands where they occur together (Barnes and Wagner 2004).
In the eastern U.S., silver maple’s large buds are a primary springtime food for squirrels, after many acorns and nuts have sprouted and other food is scarce (Geyer et al. 2010). The seeds are the largest of any native maple and provide food for many species. The silver maple is the favored host of the parasitic cottony maple scale, Pulvinaria innumerabilis.
Silver maple has diverse timber and ethnobotanic uses, and is being researched as a potential source of biofuels due to its rapid growth rate (Geyer et al. 2010).