Knowing a Tree by Skeleton, Twig and Bark
By JOAN LEE FAUST
Published: February 16, 1997
LEAFLESS trees provide wonderful opportunities for identification and observation. Their branch structure is distinctive and often exceedingly handsome. Sometimes the bark provides the strongest clue of all.
Possibly the best known trees for their remarkable bark are sycamore and birch. The native sycamores grow along streams, in wetlands along with red maples and willows. These are big trees the bark of which falls off in odd shapes, like a jigsaw puzzle, to reveal white, tan and even green underneath. Pastures and old farm sites are the places to see huge specimens of this splendid tree.
The native sycamore proved to be a weaker species than the European form, so nursery specialists developed a hybrid of the two: the London plane tree, which has proved successful as a city street tree. It withstands air pollution, limited water supply and stressed growing conditions. Besides its showy bark adds character to any neighborhood.
Birches, with their handsome peeling white bark, are found in woodlands and landscapes across the nation. They are available commercially in many forms.
One of the best known as a landscape tree is actually a European birch. It forms multiple trunks and is tolerant of poor soil conditions. The native paper birch was favored by Indian tribes for making canoes, which they fashioned by stretching the bark over a frame of white cedar.
Growing in popularity, however, is the handsome river birch. As its name suggests, this one thrives in wetter soils. Its bark has a light brown to gray hue.
Here's a good test. What about the birch tree with white bark and upside down black V's on its trunk? This mark of distinction belongs to the gray birch, a native tree that often grows in companionship with pines and scrub oaks in poor soils.
While exploring the various trees around the neighborhood, don't forget to look at the way the twigs are placed on the branches. Some are set in alternate patterns; some are opposite each other. This alternate or opposite arrangement is vital to any plant's identification and a first clue to know. Hint: most plants are alternate. To ease the learning, here's a mnenomic for those plants that are opposite: MAD HORSE: M for maple, A for ash, D for dogwood and Horse, as in horsechestnut.
The pin oak tree is an easy one to identify from a distance. First clue: all oaks have a tendency to hang onto their leaves until very late winter. The outline of their branching is always strong and the trunk has a heavy, sturdy look. The pin oak, in particular, has a most curious branch pattern. The lower branches always hang downward as if pointing to the ground.
Another distinctive pattern belongs to that rare tree, the American elm, with its elegant vase-shaped pattern. Then there is the Chinese elm, sometimes called the lacebark elm, or, in China, kwang kwang yu shu. This is a relatively new player in the landscape trade. The bark of mature specimens is extraordinary, flaking off like a sycamore's to reveal green, tan and sometimes orange underneath. The tree has a round growth pattern, as opposed to the vase shape of the American species. Yet it grows to tremendous heights.
Another tree that is easy to identify is the beech. On large estates and in parklands where a tree has room to grow, this magnificent, huge woody specimen can be glorious. Its massive trunk and size make identification simple. Especially handsome is the weeping beech with its low branches that many a child has played under. If there is any doubt to identification, take a close look at the trunk. It will be smooth, somewhat gray in color, sort of like an elephant's hide.
Among those trees that drop their bark, shagbark hickory comes to mind first. This is the tree that sheds its bark in a rather casual manner. The trunk appears as though someone tried to pull off the bark in several places, then gave up. In a similar style the katsura tree sheds its bark in a rather shaggy manner.
Another curious shedder is the paperbark maple, which unfurls its bark in small strips of a shiny cinnamon color. This tree is almost exclusively a commercial treasure and would be difficult to find in native woodlands. But where it has been planted, it proves its worth. At maturity, it is only 15 to 20 feet high so it fits nicely in the home landscape without being overwhelming. And the tree does not appear to have any insect or disease enemies.
And finally, a plug for a little-used smaller tree that deserves more attention, stewartia. This tree is not likely to be found growing in the wild as its most spectacular forms have been introduced from Korea and Japan. But all of the stewartias have a wonderful bark display at this time of year when there are no leaves. The outer bark peels off and reveals the orange-tan-brown underneath, a truly handsome effect.