A picture of the willow oak in 1973.
When you visit this spot during your tour of the Arboretum,
note how large the tiny trees growing around the oak have grown to be.
When scientists measure a tree's width, they measure the diameter at breast height, or the "dbh".* The measurement is taken at breast height—about 4 ½ feet high on an average person—because that's just about where the flare from the base of the tree ends and the straight part of the trunk begins. Of course scientists don't use people like Candace to measure, they use a tape measure. It's fun, though, to get a feel for how big a tree is by hugging every inch around it.
*If you want to impress someone who knows about trees, ask them what the "dbh" is of the oldest tree they've ever seen.
How to find the willow oak at the Arboretum:
Find the research field along Meadow Road (it's marked with a microscope symbol). Just about where the microscope is on the map, you'll see a HUGE tree standing alone in the middle a lot of small trees planted in rows.
Scientific name for willow oak: Quercus phellos
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Last Updated July 10, 2009 10:03 AM
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