The Carlisle Mosquito Online

Friday, February 6, 2009


Black Birch


Black Birch twigs showing a group of four male catkins on the center twig and the remains of a pair of fruiting cones on the right twig. The “flight of geese” on the lower right is made from scales from the cone. The twig on the left shows the remaining cone stalks after all the seeds and scales have dropped. (Photo by Kay Fairweather)

February is Black History Month and this gave me the idea of having a black natural history month and looking at the role of some of the black organisms in town, starting with the Black Birch, a native of Eastern North America.

Name: Many birch species are named for colors. In addition to the Black Birch, there are White Birch, Gray Birch, Red Birch and Yellow Birch. It is a challenge to make sense of the names. It starts off very orderly with all birches being members of the genus Betula, but then the people who wrote the income tax code must have taken over. Betula nigra, where “nigra” is from the Latin for black, is actually the name of the River Birch, aka the Red Birch. Betula lutea, where “lutea” means yellow, used to be the name of the Yellow Birch but that was too sensible and it is now known as Betula alleghaniensis. Black Birch is Betula lenta where “lenta” is from the Latin for soft or smooth and pliable. Its other common names are not as you might hope (Smooth Birch or Pliable Birch), but Sweet Birch and Cherry Birch. Not to be outdone on the confusion index, both the Paper Birch and the Gray Birch are sometimes known as White Birch.

Where seen: There are Black Birches in the Towle Field. The easiest one to locate stands where the track from the parking lot that crosses the middle of the field enters the woods on the far side of the field. Black Birch likes to be in full sun and prefers deep moist rich acidic soil. It doesn’t grow in pure stands. You’ll find it with trees like oaks, maples and beech.

Distinguishing characteristics: You can identify the Black Birch fairly easily in the winter. First, if you chew on a twig, you will taste wintergreen. This separates it from all other birches except the Yellow Birch but the Yellow Birch taste is bitter and the twigs are slightly hairy. The Black Birch has smooth twigs with a sweet taste. The catkins of the Black Birch are usually in groups of four versus groups of five or more in the Yellow Birch. This is a good winter ID aid since the male catkins for the coming spring are already formed. The bark of a Black Birch can resemble that of a Black Cherry but the catkins on the birch and the taste of the twigs differentiate them.

Uses: Several Native American tribes are known to have used Black Birch medicinally. Iroquois, Ojibwa, Delaware and Cherokee used leaves and bark to make a variety of concoctions. Its use in general folk remedies covers a long list of ailments from colds and scalds to dysentery and dandruff. For many years, oil of wintergreen was commercially distilled from the twigs and inner bark of the Black Birch. These days it is synthesized. Black Birch wood is used in the paper pulp industry and for turned products like dowels and spools. It is also used as a veneer in furniture although most birch veneer is from Yellow Birch. Black Birch wood is unique in that it darkens to a deep rich color when exposed to air and was sometimes used as a mahogany substitute.

Birch beer: To make the beer, you first tap the sap in early spring just like tapping Sugar Maples. You then induce fermentation and as far as I can tell from the “recipes” which are imprecise at best, you cross your fingers. One approach is to simply add a handful of corn to the sap and let nature do the rest. On the web I found the following recipe: “To every Gallon of Birch-water put a quart of Honey, well stirr’d together; then boil it almost an hour with a few Cloves, and a little Limon-peel, keeping it well scumm’d. When it is sufficiently boil’d, and become cold, add to it three or four Spoonfuls of good Ale to make it work...and when the Test begins to settle, bottle it is gentle, and very harmless in operation within the body, and exceedingly sharpens the Appetite, being drunk ante pastum.”

Sources: Textbook of Dendrology, William M Harlow and Ellwood S Harrar; Trees of the Eastern and Central United States and Canada, William M. Harlow; Audubon Field Guide to North American Trees – Eastern Region, Elbert L. Little; University of Connecticut Plant Database at (browse the list for Black Birch). ∆

© 2009 The Carlisle Mosquito