The papery peeling bark of the river birch is very noticeable and makes it easy to identify. Also known as black birch, red birch, and water birch, the tree’s scientific name is Betula nigra. Being a heat tolerant birch in a family of mostly cold-weather trees, it is native to the southeastern United States and is the only birch found in the southern states. This tree likes moist soil, and it can be found near the lake and other low lying areas on the YV Inner Harbour campus. It is most likely to be found as an ornamental in yards, in front of subdivisions and lining shopping center lanes. It has become one of the most popular ornamental trees, but not without problems.
One of the most appealing features of the river birch is the odd way the bark peels off in papery strips exposing cinnamon brown or reddish brown inner bark. The tree looks good even without leaves due to this exfoliating bark. However, mature trees develop ridged bark that is dark brown and does not keep the exfoliating feature. An unpopular feature of the river birch is how it drops leaves when it does not have enough water to support all its leaves. It even drops leaves when it seems to have enough water. This may be due to the requirement that its shallow roots be kept not only moist but shaded and cool. This is often difficult to arrange when giving the tree full to partial sun in warm climates. It is said that the shallow roots even starve plants around it of nutrients and water, making it difficult to grow much around it. The shallow roots may also damage driveways and foundations of houses if planted too close to them. Though the river birch is a beautiful tree, many people regret planting river birches in their yards for these reasons.
The river birch typically grows 40 to 70 feet, but in good conditions can grow to 90 feet. The trunk can be 20 to 60 inches in diameter, and there are usually multiple trunks. The leaves are alternate and simple, with teeth on the edges that also have small teeth between the larger teeth. They are flat and elliptical with broader bottom, and are usually 1.6 to 3.1 inches long, and 1.2 to 2.4 inches wide. There are 5 to 12 pairs of veins, running parallel from the midrib. Leaves turn yellow in the fall. The tree produces male and female flowers called catkins. The male catkins are pendulous and the female catkins are erect and appear somewhat like a brown cone. The fruit is composed of numerous tiny winged seeds packed between the catkin bracts. The seed matures in the fall and is spread by the wind.
Historically, Indians have used the boiled sap as a sweetener similar to maple syrup. The sap has also been used to make birch beer and vinegar. The leaves have been used as a cure for dysentery. The wood is durable and easy to work with and has been used to make furniture and wooden ware like artificial limbs, flatware, and toys. However, it is too knotty and contorted to be of use as a timber tree.
The river birch is an interesting tree, with features that make it an excellent ornamental. With careful consideration of all the tree’s qualities, this tree can be enjoyed not only in its natural environment but as an eye-catching landscape specimen. It is one of my favorite trees.