Summary ³

Betula nigra (black birch, river birch, water birch) is a species of birch native to the Eastern United States. It is one of the few heat-tolerant birches in a family of mostly cold-weather trees which do not thrive in USDA Zone 6 and up. B. nigra commonly occurs in flood plains and/or swamps.

Description ⁴

Family:
Betulaceae (Birch)

Height:
50 to 90 feet at maturity

Habit and Lifespan:
Single or multiple-stemmed tree; Irregular to rounded-pyramidal crown shape; DBH up to 3’; Short-lived

Leaves:
Leaves (up to 4” long and 2½” wide) are alternate, oval in shape, and have deeply double-toothed margins and pointed tips.

Bark:
Younger bark is reddish-brown and extremely flaky, with the outer layers peeling away in large, thin plates to reveal a layer of smooth pinkish, orange, or cream-colored bark underneath. Mature bark is gray-brown and coarse, and significantly less flaky than younger bark.

Flower:
Male flowers grow in groups of 1-3 cylindrical catkins (1½-3 ½” long), which are greenish yellow to yellow-brown in color, and dangle from the tips of the twigs. Female flowers are similar in color, but grow as erect catkins (up to ½” tall) from the same branches as the male flowers.

Fruit:
Female catkins produce many small seeds. Individual seeds (up to ¼”) are papery, flat, winged nutlets, which begin green in color and become brown as they dry.

Bloom time:
April-May

Fall color:
Golden Yellow

Nicknames:
Water Birch, Black Birch

Habitat:
This species prefers full to partial sun and moist soils. It tolerates a wide range of soil types, including disturbed and acidic soils. It is commonly found growing in floodplain woodlands, along rivers and lakes, in drier areas of marshes and swamps, and in landscaping settings.

Wildlife Benefits:
Various parts of the tree provide food sources for many species of birds and insects, as well as squirrels, deer, and rabbits. Wood is used as a source of food and building materials by beavers.

Notes:
River Birch is a popular landscaping species. Due to its tolerance of disturbed and acidic soils, it has also become a popular choice for use in reclamation of areas like old mine sites that have contaminated, acidic soils.

The wood of River Birch is knotty, and thus has low commercial value in terms of timber production; however, it is strong and lightweight. As a result, River Birch was historically used as an inexpensive source of wood for prosthetic limbs.

References:
https://www.minnesotawildflowers.info/tree/river-birch
https://www.illinoiswildflowers.info/trees/plants/river_birch.htm
https://plants.ces.ncsu.edu/plants/betula-nigra/
https://www.fs.fed.us/database/feis/plants/tree/betnig/all.html

Range ⁴

Sources and Credits

1. (c) Maggie, some rights reserved (CC BY-NC), http://www.flickr.com/photos/13389908@N03/1820801175/
2. (c) Ramsey-Washington Metro Watershed District, all rights reserved, uploaded by Ramsey-Washington Metro Watershed District
3. Adapted by Ramsey-Washington Metro Watershed District from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Betula_nigra
4. (c) Ramsey-Washington Metro Watershed District, some rights reserved (CC BY-SA)

More Info

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