Black Birch or Sweet Birch
Scientific name: Betule lenta
Of the fifteen species of birch in North America, six can be found here in Lewisboro. The black birch is distinctive as it can be very long lived and grow to 100 ft. If you scratch a twig of this tree you will note the distinctive aroma of wintergreen. The bark of this tree is unique as it is quite smooth, as pictured for the first 30 to 40 years of life. It grows quickly in height, but not in circumference. Should it be in a spot that meets its needs with plenty of light, it can continue to grow for hundreds of years! Overtime, its original bark will shed and new bark will take its place. With age, it will fracture and plate, having a whole new appearance. In the forest, you will sometimes see blue-green lichens growing on its bark. When it falls, it decomposes quite quickly.
Habitat
This tree requires a spot that get light to grow. In circumstances where other trees, like the hemlock die due to disease, the birch will take advantage of the new sunlight and its seeds will germinate.
Fruit
The cones will appear in late summer and fall. The ripened seeds will shed off the cone with the wind.
Flowers
Male catkins bloom in late summer and in spring they fertilize the female flowers which will tern into the fruit (cone).
Ecosystem Connections
Deer do not browse on these young trees, giving them an advantage to survive over other trees.
Human Connections
For many years, this tree was used in the production of wintergreen oil.
More on Trees and Shrubs in Lewisboro
Lewisboro was once entirely forested except for patches of open field caused by fire and wetlands and ponds which were expanded by beaver dams. Although it is hard to believe, by 1800 most of Lewisboro’s forests had been cut down and replaced by farms. In 1820 so many trees had been cleared that there was no shade anywhere along the route from Boston to New York.[1] But by the mid-1800’s farming here became uneconomical and as farms were abandoned, the forests began to re-grow. Today, 70% of New York is once again forest, what some call ‘the great environmental story of the United States’[2]. These new forests provide us with beauty and recreation, clean air and water, flood control, erosion prevention, carbon sequestration, cooler temperatures and habitat for other plants, insects, birds and other wildlife.
[1] Cronon, William. Changes in the Land. Macmillan, 1983.
[2] An Explosion of Green. B. Mckibben. Atlantic Monthly 275 (April 1995): 61-83.