Acer platanoides is a tree that usually grows to 40-60 ft. (12-18 m) in height, but can reach heights of 100 ft. (30 m). The bark of the tree is grayish and regularly and shallowly grooved.
Foliage
The palmately lobed leaves are opposite and have 5 to 7 sharply acuminate lobes (with large but few teeth). These leaves are 4-7 in. (10-18 cm) wide. The leaf petioles exude a white sap when broken. The leaves are usually green in color, but there are some cultivars that have dark red leaves. The fall color of the green leaves is yellow.
Flowers
The flowers appear in April and May and are yellow-green in color. They are borne in erect, pedunculate, rounded corymbs. Each flower is 0.25 in. (5-6 mm) wide.
Fruit
The pendulous fruit measure 1.5-2 in. (4-5 cm) in length. The fruit are samaras that are green when young and turn yellow, then brown, with age. The samara wings are divergent, reaching nearly 180 degree angle to each other and are dispersed by wind.
Ecological Threat
Acer platanoides is able to shade out native understory vegetation such as spring ephemerals, and eventually out-competes native tree species in the forest canopy. Thus, it can reduce native species diversity and change the structure of forest habitats.