Looking Beyond the Obvious

Winter is here, the leaves have been raked away, the blooms have faded and disintegrated into compost, the ornamental grasses are brittle and of a maize hue, life is in shades of grays, blues and browns outside, or maybe you just aren’t looking deeply enough. 

There is a spectacular display of color and texture happening with Mother Nature’s pupils right now, and while it might not be glaringly obvious some of life’s most outstanding shows are in the minutia if we just bother to really examine.  The art of bark is at its best now when the leaves have plummeted to the earth, the berries have been nibbled away by the birds and all that is left is a textural kaleidoscope in the armor of a tree.  Bark is much more than a rough blanket of protection, each species has a unique pattern that serves as a means of identification, and in that armor we can see the hardships and bounties of that particular tree, we can guess at it’s age and of catastrophic weather calamities the tree has endured.  Regardless if that resistant coating is red, green gray, white, orange, striped, thorny, smooth, rough, furrowed, papery, whether the layers peel away to reveal a mosaic of multiple colors or the deep shadows of the sunrise look like abstract art on a thick, old trunk, the beauty is there we only need to take note.

The Science of Bark

“To the trained eye, most tree species can be identified by the bark and buds.”  States Dr. Charles Barden, Associate Professor of Forestry at Kansas State University, he adds, “This is useful, since the leaves are off the trees from November to April.”  Bark textures are divided into at least 18 types, from smooth (like the beech tree) to spiny (like the locust).  The variations of markings, colors and texture denote not only the type of tree, but even the age of the tree.  A comparison would be like that of the human’s skin, it comes in a variety of colors, it can reveal our ages and it protects us from the elements. 

The bark is a portal for the distribution of food in the tree, how does that work?  Dr. Barden explains, “Bark is made up of two kinds of tissues, the inner bark also called phloem layer, which is just one cell thick and is used by the tree to carry sugar made in the leaves down the trunk and to the root system.  The outer bark is what we see and is made up of dead cells, which serve to insulate and protect the delicate tissues beneath (phloem and cambium).  Old trees can have very thick bark, which can make them quite resistant to fire damage, for instance, some large cottonwoods in this area may have an outer layer up to 3 inches thick!”

So the inner layer of bark or the phloem of the tree is moist and soft allowing for the passage of food this layer also rids the tree of wastes by absorbing and locking them into its dead cells and resins.  Older trees have thick bark because annually a layer of the inner bark hardens and becomes part of the outer bark.  As an example, the bark of the giant and ancient west-coast Douglas-fir tree may be more than a foot thick! 

So, what about the color variation in a trees bark, why are some a wash in brilliant colors while others are not?  Barden states, “It has to do with the make up of the layers of cells in the bark.  On sycamores, the outer gray bark flakes off and reveals light green and light gray bark layers.  Other trees have homogenous bark layers, and they do not fall off in large pieces so the appearance does not change, much like an oak tree.”

The Contributions of Bark

The origin of aspirin came from the bark of the willow tree.  The development of an anti-malarial drug quinine came from the bark of the Cinchona tree.  Tamoxifen, a common drug used today to prevent a recurrence of breast cancer, comes from the Pacific Yew tree.  Clearly, not only do these towering forces contribute a wealth of beauty in the bleakest of months but they provide a bevy of hope and cures to boot. 

Displaying Bark

When thinking about this textural winter show keep in mind that in those chilly months you want to view your trees from the inside, so plant new trees with an optimal vantage point when indoors.  Be mindful of the weed-eaters and mowers to help keep trees bark healthy- gashes can serve as an entry point for pests.  You might consider a bed around the base of the tree or a ring of mulch to avoid this problem.  For some trees, like the birch, it is lovely to have a few planted together to create a repeating pattern and their bark display will have more impact.   Dr. Barden suggests, “Two easy to grow trees here in Kansas with beautiful bark are the London Plane tree and the River Birch.  The London Plane is a hybrid of the Native American Sycamore and it is not prone to a foliage disease that strikes the sycamore in wet springs.  It does get rather large (50-60 feet tall with a wide crown) too large for some home settings.  River Birch does not get as big (40-45 feet tall with a narrower spread) and has attractive salmon colored patches that are revealed as the brown outer bark peels away.”

So, get out there, bundle up and take a slow walk around Lawrence.  Look deeply at the trunks of trees and you will find the display is fantastic and awe inspiring.

Trees with Interesting Bark:

• Red Cedar
• Dogwood
• Bald Cypress
• Sycamore
• Black Cherry
• Japanese Maples
• Carolina Silverbell
• Shagbark Hickory
• Paperbark Maple
• Stewartia
• Beech
• Birch
• Snake Bark Maple
• Crape Myrtles