Black Gum
Nyssa sylvatica

Location in Ontario

Black Gum is a Carolinian Tree found in Lambton County, Essex County, Middlesex County, Chatham-Kent, Norfolk County and the Niagara Region. it grows on low wet ground around streams or in swamps.

Fall colours of old growth Black Gum in Backus Woods, Norfolk County

Genus Nyssa
Leaves are simple and alternate. Nyssa are found in wet habitats. The wood is fine textured and strong. The trees are dioecious with male (pollen) flowers and female (seed) flowers occurring on different trees. The fruit is a berry. In Ontario, the only species of Nyssa is Black Gum.

In the Landscape
Black Gum is a slow growing, medium sized tree grows to 20 metres and can live to be 600 years of age! It makes an outstanding medium sized landscape tree, with its handsome glossy leaves and brilliant fall colours. The bark and form make an interesting specimen in the winter. However, Black Gum requires a lot of moisture.

TREE FACT: Black Gum, also called Sour Gum, does not produce gum at all; it is named gum because of similarities to Sweet Gum. It is also called Pepperidge or Black Tupelo, tupelo meaning swamp tree.

Black Gums in a row, Wheatley Provincial Park

The leaves are alternate and simple, thick and glossy with smooth edges. In the fall, leaves can be yellow, orange, scarlet, red or purple. Leaves are often mottled with colour, rather than turning colour completely.
The bark is dark gray and broken into rectangular shaped ridges. It is said to resemble alligator skin.
Black Gum is mostly polygamo-dioecious with male (pollen) flowers and female (seed) flowers occurring on different trees, but occasionally has perfect flowers . Flowers are greenish-white in colour and tiny. Female flowers are in sparse clusters and male flowers are in dense clusters. Flowers appear in early June after the leaves are out. Flowers are pollinated by insects; especially bees.
The fruit is a black berry (drupe) that is oily and sour. The fruit appears in early summer and ripens in late September. Fruit production is variable. No data is available for the age that Black Gum produces fruit. 

TREE FACT: The nectar of Black Gum leads to outstanding honey. In fact, Black Gum Honey is often considered to be the finest of North American trees.

Black Gum leaves can be a very deep red

The wood is medium hard and heavy. Black Gum is used for veneer and crates. Due to its double, twisting grain, it is extremely difficult to split for firewood. 
Specific Gravity: 0.50
Janka Hardness: 810 lb
Wood Comparison Chart

Two Black Gums, and one fallen. Wheatley Provincial Park

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