A blue gum tree.
blue gum definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a large evergreen tree (Eucalyptus globulus) of the myrtle family, native to Australia, having smooth, deciduous bark and aromatic leaves: grown extensively in California
blue gum definition by American Heritage Dictionary
A tall timber tree (Eucalyptus globulus) of Australia, having smooth, bluish deciduous bark and lance-shaped aromatic leaves.