As a recent resident of New England, I am still thrilled when I see a stand of birches in the forest. I love this tree for both its beauty and its usefulness: when camping, there’s no better firestarter in wet weather than the oily paper bark of a downed birch. But why is this tree so different from other trees? Why is its bark not fire-resistant, its lack of color so shockingly bright against multitudes of drab trunks? Why has it inspired so much poetry?“Is it agony that has bleached them to such beauty? Their stand is at the edge of our property–white spires like fingers, through which the deer emerge with all the tentative grace of memory.”
– Nathaniel Bellows
That pale bark is arguably the distinguishing characteristic of a birch. To understand why it is different, we must first think about the bark of other trees.
In the most generalized sense, bark is the outer covering of woody plants, encompassing everything outside of the vascular cambium. There are several layers that make up “bark,” which are (moving from the cambium outward): the phloem, cortex, phelloderm, cork cambium (phellogen), and cork (phellem). In most trees, bark serves as protection against loss of water by evaporation, attacks by insects, drastic temperature changes, and disease. In some trees, it even acts as protection against fire damage. Except for the last, all of these functions are served by the fine, papery bark of a birch. What makes the birch unique is what its bark contains that other trees do not.“After a storm, one birch fell in the field, an ivory buttress collapsed across the pasture. Up close, there is pink skin beneath the paper, green lichen ascending in settlements of scales. In the dark yard it beckons you back” -Nathaniel Bellows
The chemistry of birch bark is what conveys its most amazing properties, and most likely is what secured this tree’s place in folklore, mythology, and poetry. Birch bark is white because of the presence of a phytochemical, called betulin. The total content of betulin ranges from 15-25%, depending on the species. Betulin is hydrophobic, meaning that it resists water. The whiteness (protection against light damage) and the water resistance led to birch bark being used in construction of canoes by native Americans. Both betulin and its derivative, betulinic acid, are being studied for medicinal uses against melanoma, herpes, and HIV.“The trunks of tall birches Revealing the rib cage of a whale Stranded by a still stream” -William Jay Smith
Throughout history, humans have found a way to use nearly all the parts of the birch, so much so that it is often referred to as the “giving tree.” It has an amazing ability to survive harsh circumstances, and is a first successional tree, quick to repopulate areas that have succumbed to fire or clear cutting. (Though I couldn’t find data on this, I wonder if this ability is the reason its bark is not fireproof: fire is actually advantageous to a birch because it eliminates competitors and allows a chance to recolonize). Because of its abilities, the birch has acquired quite a bit of symbolism in different cultures. In Celtic cultures, the birch represents growth, renewal, stability, initiation, and adaptability. In Gaelic folklore, it is associated with the land of the dead, and appears often in Scottish, English, and Irish folklore in association with fairies, death, or returning from the grave. A tree with such near-legendary qualities and capacity for survival–how could it fail to inspire wonder?“its bark papyrus, its scars calligraphy, a ghost story written on winding sheets, the trunk bowing, dead is my father, the birch reading the news of the day aloud as if we hadn’t heard it, the root moss lit gas, like the veins on your ink-stained hand– the birch all elbows, taking us in. -Cynthia Zarin
“Birch,” by Cynthia Zarin. Read it here.
“Birch,” Wikipedia. Link.
Krasutsky, Pavel. 2002. “Birch Bark Extractives.” University of Minnesota-Duluth. Link.
“Russian Birch,” by Nathaniel Bellows. Read it here.
“Winter Morning,” by William Jay Smith. Read it here.