Sunday, August 31, 2008

Student Post, River Birch

BETULA NIGRA (River birch), Betulaceae family

Betula nigra, what a discovery!

I did not know this tree. In fact, I did not know any trees (except for plane trees, Christmas trees (lol!) and the trees of my region – I am from the South of France - so, olive trees and lindens (tilleul)), before I met Jennifer.

Betula nigra is such a fascinating specimen.

It starts as a local story.

Originated from throughout the southeastern United States (from New Hampshire west to southern Minnesota, and south to northern Florida and east Texas), river birch is commonly found in flood plains or swamps (River birch is the most common species on the banks of disturbed streams in Tennessee), is closely associated with alluvial soils and grows near willows.

River birch wood is hard, strong but of limited commercial value since it is usually too knotty to be used for lumber. Its main uses are for local furniture manufacture, basket materials, small woodenware, and fuel.

Native Americans used the boiled sap as a sweetener similar to maple syrup, and the inner bark as a survival food.

Recently, Betula nigra (together with gray birches (Betula populifolia) have become the beloved of “modernist” (that is to say, minimalist) architects and landscape designers.


Its relatively small-diameter trunk, combined with the beauty of its bark – brown, reddish, pinkish bark peeling off in film-like papery curls all year round – provides for a sophisticated element of verticality in a space. Its papery texture refers to “art brut” and coexists extremely well with contemporary architecture.

Also, its branches are…black, which is quite dramatic,…

and drooping, particularly when they are wet with rain.

Foliage is delicate and lets the sun filter through, providing a light atmosphere to the ground where Betula nigra is planted.

Plant Characteristics:

40 to 60’ high and 25 to 35’ wide, with an oval, pyramidal, symmetrical canopy

fast grower, and likes sun. Monoeicious.

Leaf is simple, double serrated, ovate, deciduous, green in the summer and yellow in the fall.

If left unpruned, it often becomes multitrunked in its first or second year.

Tolerant to clay, loam, sand, acidic, extended flooding, low soil oxygen.

Pendulous catkins are characteristic. Producing abundant pollen and therefore contributing to hay fever.

Seed production and seedling development.

Good seed crops are usually produced annually. The winged seeds are wind or water disseminated. Water dissemination is probably more important because water deposits the seeds on moist shores favorable togermination and establishment. It is an early pioneer on stream bank alluvium, and requires high soil moisture coupled with no shade for germination and establishment.

“The most beautiful of American trees!”. That’s what Prince Maximilian thought of river birch when he toured North America before he became the short-lived Emperor of Mexico. I concur!

To end:

Let us not omit that Icelandic singer and actress Björk Guðmundsdóttir, known simply as Björk. She bears a fine, ancient Viking name meaning ‘birch tree’!

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