Oaks are generally divided into two major groups: red oaks and white oaks. Red oaks have bristle-tipped leaves, acorns with hairy shell linings and bitter seeds that mature in two seasons. White oaks have leaves lacking bristles on the lobes, acorns with a smooth inner surface that are sweet or slightly bitter and mature in one season.
Bur Oak (Quercus macrocarpa). also called Mossycup Oak, is in the white oak group and is easily identified by the corky ridges on its young branches, deeply furrowed bark and acorns with knobby-scaled caps (cupules) with a fringed edge. This member of the beech family (Fagaceae) derived its common name from the resemblance of its heavily fringed caps to the burs on a Chestnut tree, though the caps only half cover the nut. Common in central U.S., Bur Oak is relatively uncommon in New England, occurring in in central Maine, New Hampshire, the western edges of Massachusetts and Connecticut, and the Champlain Valley in Vermont.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.