Water Birch

Growth Characteristics: A small tree, usually shrubby in appearance, that averages less than 20 feet in height, and stems that average less than 8 inches in diameter. Many stems usually arise from the ground from a common area giving the crown a spreading or open appearance. It reproduces by seed.

Flowers/Inflorescence: Small (about 1 inch long), cylindrical, cone-like structures (catkins or aments). Between the scales of this "cone" grow the seeds that are tiny nutlets. As the "cone" ripens, the entire structure disintegrates, and the seeds are dropped. Male aments are smaller and in clusters.

Fruits/Seeds: A broad-winged samara, with minute nutlets and narrow, lateral wings.

Leaves: Broad, oval to somewhat elongate, about 1-½ inches long, with a short pointed tip. The margin of the blade is sharply toothed with fine teeth inside the larger ones. The leaf petioles are short and dotted with tiny glands. Leaves are shiny green through the summer until they turn brown and fall in the autumn.

Stems: Twigs are slender and drooping. The green to reddish-brown bark is roughened by many small lenticels (glands or air openings). Bark is thin and peels in layers around the stems, is smooth, shiny, and copper-colored, even on old trunks. The surface is conspicuously marked with horizontal lines (lenticle scars) that enlarge as the stem grows. Buds are small, red-brown, and very resinous. Wood is soft, light brown, and strong.

Ecological Adaptations:

Water birch is mostly restricted to mountain stream banks and very moist canyon bottoms between 4,000 and 8,800 feet elevation. It is very tolerant of flooding.

Water birch has very high nutritional requirements especially for magnesium and calcium. Both elements are normally available for uptake where it grows.

Soils: Water birch occurs on a wide variety of soil textures. Coarse-textured soils are most common, and most soils containing at least 35 percent rock fragments.

Associated Species: Willows, cottonwoods, alder, aspen, wild rose, and boxelder.

Uses and Management:

The primary importance of Water birch is for streambank stabilization and wildlife habitat. It is valuable for shade and cover for fish in mountain streams. It also provides valuable shade for recreation sites.

Water birch has limited use, mainly for fuel and posts. It is only lightly browsed by most classes of livestock. The willowy, slender stems have made many hasty fishing poles. Native Americans used a tea from Water birch as a diuretic. A strong solution was reported to break kidney stones and ease their passage. The juice from young leaves was used for skin irritations.

USU Extension | Intermountain Herbarium | College of Natural Resources
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