Friday, November 2, 2012

The Birch with the chronic bad bark days.

Species name: Betula nigra

Common name: river birch, black birch

Location: Ontario

The river birch is a species of tree native to eastern North America, but the native range doesn't quite squeak up into Canada (the northernmost point in its native range is about Ohio), but it has been naturalized here and is now quite common. The bark is incredibly distinctive; to me it looks almost like a birch with a bad bark day. The tree is called the river birch for a reason; it is often found on river banks where the soil is often flooded, but not completely submerged in water (but it can withstand seasonal flooding, as long as the water retreats and the soil dries during the summer).

When young, these trees have many lower branches and look relatively "bushy". After a few years, the trees can self-prune away the lower branches to start to look more like a tree. Because of this pruning and previous branch growth, adult tree wood is very knotty (branches are what make knots in wood). In general, knotty wood is not favoured for anything other than pulp, particleboard, or firewood since the wood grain in the knot is going at a different angle than the wood grain in the rest of the plank of wood. This means that as the wood expands and contracts (with temperature, moisture, drying after initial cutting, etc.), the wood will bend and warp due to the knots. For this reason, black birch is very rarely used as a lumber tree.

Believe it or not, maple trees are not the only trees where Native North American people used to get an edible syrup. The black birch can be tapped during the spring exactly like a sugar maple can, the resulting sap boiled to reduce the liquid, and used as "birch syrup." It has a very different flavour than maple syrup, but no less good. Sugar is sugar, after all! It's the impurities that make the taste.