Black Maple
Acer nigrum

Location in Ontario

Black Maple grows in the Deciduous Forest and along part of the St. Lawrence River. It grows on moist floodplains.

Fall colours of Black Maple, University of Guelph Arboretum

Genus Acer
Maple trees have simple, lobed leaves that are opposite and decussate (successive pairs are 90 degrees to each other). Check this link for more about decussate leaf arrangement.

Maples are known for their beautiful fall colours. Maples are monoecious with male (pollen) flowers and female (seed) flowers on the same tree, although some species are solely male or female. Seeds are in double-winged samaras, or keys. Sugar Maple, Black Maple, Red Maple, Silver Maple and the hybrid Freeman's Maple all grow in Ontario.

TREE FACT: Maple trees are divided into "hard" maples (Sugar and Black) and "soft" maples (Silver, Red and Freeman's).

In the Landscape
This large tree grows to 35 metres and lives to about 200 years of age. Black Maple is a beautiful large tree, with a full canopy, that needs a lot of space.

TREE FACT: Black Maple and Sugar Maple are very similar but with noticeable differences in the leaves. Black Maple can be found in wet conditions where Sugar Maple do not occur. In other places, they occur together and often hybridize producing new trees with characteristics of both.

Black Maple, University of Guelph Arboretum

Black Maple leaves are similar to Sugar Maple, but have three lobes, and a wilted appearance. Leaves turn yellow to deep gold in the fall.
The bark is nearly black, and deeply furrowed.
Black Maples are monoecious with male (pollen) flowers and female (seed) flowers on the same tree. Flowers are variable; male and female flowers may appear in the same cluster, or in separate clusters. Flowers appear in early spring before the leaves. Pollination is by wind.
Black Maple seeds are contained in keys (doubly-winged samaras). Keys twirl to the ground, dispersed by wind and water, in the fall. Black Maples produce fruit after 30 years, with heavy seed crops every 4 years. 

Black Maple seedlings, St. Williams Nursery and Ecology Centre

Black Maple and Sugar Maple have hard wood, and are collectively known as "Hard" Maple. Hard maple wood makes beautiful cabinets, furniture, flooring etc.  
Specific gravity: 0.57
Janka Hardness: 1180 lb
Wood Comparison Chart

Although Black Maple has distinct characteristics, it is genetically the same as Sugar Maple, indicating that it is in fact a sub-species. It also readily hybridizes with Sugar Maple.

Try these links for interesting reading about Black Maple:  Morphological-differences between-black-maple-and-sugar-maple  and  RAPD reveals genetic similarity of Acer saccharum and Acer nigrum

Golden leaves of autumn, University of Guelph Arboretum

Link to United States Forest Service Silvics Manual for Black Maple.