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Friday, February 20, 2009

2/20/09 THE EVERGREEN THAT'S NOT



Friday, 8:30 AM. 5 degrees, wind W, calm. The sky is covered with light, hazy clouds but the sun is shinning through and it may clear up. The barometer predicts snow.
The trees pictured are tamaracks, Larix laricina, common in wet areas, bogs, etc. but also on drier sites throughout northern Wisconsin and Minnesota, the Great Lakes States, New England and much of Canada. It is a conifer that sheds its needles, is deciduous like broad leafed trees, and therefore is not an “evergreen.” There are related species in Europe and Asia that have the same general characteristics. The bald cypress of southern states also sheds its needles in winter. When trees (and shrubs) are deciduous they are exhibiting an adaptation which conserves water in the plant, winter being a very dry season. Woody plants are also often deciduous in climates that have very distinct wet and dry seasons. Evergreen conifers are more ancient evolutionarily that almost all deciduous trees, and most never developed the deciduous characteristic. Evergreen trees, however, retain the advantage of being able to photosynthesize even during the winter, so have used that trait to continue to survive and compete with the more advanced deciduous species. Evolution is not always an either/or situation, ancient and modern often competing with each other over vast stretches of time, and the ancient sometimes out-competes its newer rivals, particularly in odd habitats or niches. In any case, the tamarack is an interesting tree. In spring its new foliage is feathery light green, very refreshing, and its new cones are almost flower-like, a colorful rose-purple. Its summer foliage is dark green and soft, and its golden fall color outstanding. It is effective in naturalizing large areas, and is an unusual accent tree. Because it is deciduous, it can be planted on the south side of a house and still let in the winter sun. As you can see, I am very fond of this “evergreen that’s not.”

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