A Tree of Too Many Names

The box elder trees along the wayside are now leafless, but certainly not barren. Their branches are heavy with hanging clusters of paired winged fruit, or keys, that will last through the coming winter and into spring. The seeds, one to each key, are an easy food source for squirrels, mice and birds like evening and pine grosbeaks. And that's probably the nicest thing you can say about an oddly and variously named native species that few people would consider a prized shade tree, though it was widely planted for that very purpose in times past. In fact, there's a town called Box Elder in South Dakota and a Box Elder County in Utah.

Box elder seeds in November (By Les Line)

But as the naturalist John Eastman wrote in a delightful volume titled The Book of Forest and Thicket, the box elder "is often regarded as a weed tree because of its prolific sprouting and its tendency to lean, shed branches and generally ignore human standards for an attractive tree." Some states consider it an invasive species. On the plus side, box elders do grow fast and almost everywhere, thriving especially in wet bottomlands. There's a spurt of growth in the first 15 or 20 years and then the tree slows down for another 75 or so years. A mature box elder might reach a height of 65 feet, not much more.

As for the name, the box elder is not related to the elderberries with their juicy red or purple fruit. Presumably, early American settlers who were familiar with elders back in England saw a similarity in their foliage. And its wood is said to be whitish like that of an Old World evergreen shrub called the common box. Hence, the box elder. (Given its name, it seems ironic that the tree's lightweight wood has little commercial value-- except for making boxes or crates.)

New box elder leaves in spring (www.hiltonpond.org)

In fact, box elder is an aberrant member of the maple tribe with trifoliate leaflets that more closely resemble those of an ash tree than, say, the single leaf of your typical maple. Which is why some tree guides prefer the name ash-leaf maple. And to really confuse matters, box elder is known in different regions of the country as black ash, stinking ash, sugar ash (Plains Indians boiled the sap), cut-leaf maple, three-leaved maple and, in Canada, Manitoba maple. For that matter, there's no agreement on how to spell the tree's most common name: two words (box elder), hyphenated (box-elder) or one word (boxelder). It's a good thing we have all those Latin names for plants and critters. Box elder, for the record, is Acer negundo, and for more photos check out this Trees of Wisconsin page. 

Then there's the matter of the strikingly marked boxelder bug, which is native to the Southwest but reached New England in the 1940's, congregating every fall on the thousands of box elders that had been planted along city and village streets. And also massing on the warm, sunny sides of homes, which they are known to enter in search of a place to hibernate. The University of Arkansas Arthropod Museum notes that the bugs will wander around the house on warm winter days and can stain furniture and drapes with their excrement. Another good reason to take the chainsaw to that unlovely box elder tree in the backyard.


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