Betula nigra (heritage) 

Heritage® Riverbirch

Form: Pyramidal to oval-headed in youth, often rounded in outline at maturity.

Size: 1.5-3.5" long;3/4-2.5" wide
Zone: 3B to 9.
Leaves: Rhombic-oval, sharp pointed, base wedge shaped, doubly serrated leave with a glossy dark green color turning to a rich yellow in the fall.
Bark: Starts to exfoliate on young trunks and opens to a white to salmon-white on young stems, eventually darkening to a salmon-brown as it matters.
Fruit: Small nuttlet, born in a 1-1.5" long, .5" thick cylindrical, pendulous catkin, which ripens and sheds in the spring. 
Flowers: Male in 2-3" long, slender dark brown catkins.
Growth Rate: Medium to fast. Can grow 30-40' over a 20 year period.
Description: Grown as a multi-stem this tree thrives in large areas that are wet for much of the year, it is the most trouble free birch and is extremely well adapted to the heat.