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Bur Oak: An Uncommon Source of Acorns in the East

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.

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5 responses

  1. Alice

    I need to really learn how to ID oaks.. Pin & Black Oak, too.

    October 9, 2020 at 3:42 pm

  2. Jon Pringle

    Bur Oak is can be found near Taft Corners, Williston. Back in the 1980’s I had the pleasure of putting these oaks under the spotlight with Hub Vogelman, a professor of mine when at UVM in the ’60s. Hub was president of the Nature Conservancy at this time.
    We mapped out the oaks before and and in opposition to mall sprawl. If you wish to see one, If you stand near the entrance to Best Buy, look towards Old Navy then look left. You will see a large tank, possibly holds water, Bur Oak will be found close by the tank. These trees are also growing up in the Islands. They are otherwise uncommon in Vermont.

    October 9, 2020 at 5:15 pm

  3. Bruce Flewelling

    I collected some Bur Oak acorns from Addison County and now have 2 trees in my yard in Windsor County!

    October 10, 2020 at 4:57 am

  4. serenityrose04hotmailcom

    Good morning Mary,

    You made my day and clarified acorns, two-year cycle tip someone shared. Love volunteering with Project Wild in MA with Pam Landry. She talks non-stop and I use your great book all the time!

    Your photos and those donated are exquisite and you have connected forever to my inner child!

    stay safe and thank you,

    Viola Rose ________________________________

    October 10, 2020 at 9:27 am

  5. So, do bur oak acorns have lots of tannin like red oaks, or less, like white oaks?

    October 10, 2020 at 11:53 am

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