Америка битісі: Сирек кездесетін қара қайын ағашы

Species of birch

Betula nigra, the black birch, river birch or water birch, is a species of birch native to the Eastern United States from New Hampshire west to southern Minnesota, and south to northern Florida and west to Texas. It is one of the few heat tolerant birches in a family of mostly cold weather trees which do not thrive in USDA Zone 6 and up. B. nigra commonly occurs in floodplains and swamps.

Betula nigra is a tree that falls into the family of Betulaceae, which is commonly known as the Birch or Alder Family. This family comprises six genera (Alnus, Betula, Carpinus, Corylus, Ostrya, and Ostryopsis) and includes alders, birches, hornbeams, and hazelnuts. Species within this family, along with Betula nigra, are shrubs or trees that grow along stream sides or in poorly drained soils throughout the Northern Hemisphere. Betulaceae is included within the order Fagales, which branches from the Rosid clade.

The river birch is often found in low elevation regions from as north as Massachusetts to as south as northern Florida. It can be found extending west to Kansas and east to the coast where proper habitat conditions occur. As its name depicts, this birch is found along stream sides. It can also be a prominent species found in forested wetland communities and in areas containing moist soil, such as floodplains. River birch is best placed in USDA hardiness zones 4–9.

It is listed as threatened in New Hampshire.

In states in which mining is prevalent, the river birch is often used for reclamation and erosion control, as it is well suited for soils that are too acidic for other species of hardwoods. In West Virginia, they have been found to establish within mine refuse sites after being blown from neighboring areas.

Seeds are typically produced annually. Seasonal development begins in the fall as male catkins begin to form and mature. The emergence of female catkins corresponds with the return of leaves around early spring. Male and female fruit matures during the spring season or in the early summer months. Native Americans used the boiled sap as a sweetener similar to maple syrup, and the inner bark as a survival food. The combined essential oils are phytotoxic to lettuce (Lactuca sativa) and perennial ryegrass (Lolium perenne) seedlings. They have also demonstrated insecticidal, nematicidal, and antibacterial properties.