Quercus nigra 

Water Oak

Form: Conical to round-topped.

Size: 50-80'
Zone: 6 to 9.
Leaves: dull bluish green to a lustrous dark green.
Fruit: Acorn. Usually solitary, 1/2" long and wide.

Flowers: Slender dark brown catkins.
Growth Rate: Medium to fast.
Soil Tolerances: Moist-wet. Inherent soil tolerance.