Friday, October 15, 2010

Shagbark Hickory

Blue Jay Barrens is fortunate to have a woodland composed of a wide variety of deciduous tree species. One of my favorites is the Shagbark Hickory, Carya ovata. The loose, flaky bark makes the origin of the common name obvious.

The curling bark provides shelter for numerous insects, mammals and birds. Bats commonly roost in the shelter of the loose bark and I’ve found Comma butterflies spending the winter squeezed between bark and trunk. Woodpeckers and Nuthatches spend a lot of time pulling insects out from under the bark flakes. Occasionally I’ll find a long strip of bark that has fallen off during the winter and I wonder what dormant life form might have lost its protection.

It takes a little more than just looking at the bark to properly identify this hickory. Another species, Shellbark Hickory, also has the loose bark, so it becomes necessary to check leaves, buds, twigs and nuts to properly sort out the two. Most of those parts are kept out of reach in the upper canopy, so it’s fortunate that the nuts come to the ground each fall.

Shagbark Hickory has a medium sized nut covered by a thick, four-sectioned husk. The nut has distinct ridges running along its surface.

There must be a weevil for every nut, because the round exit holes are common to many types of nuts. This hole is the work of the Hickory Nut Weevil, which has a larva that develops inside the nut and then cuts its way out to continue its development on the forest floor. These guys must have some tough mouth parts to cut through that shell.

As far as I know this beetle has no particular association with hickory other than the coincidence of its landing here while I was looking. I believe this to be a Cedar Beetle, Sandalus niger, although I’m not positive. Those antennae are incredible. As I write this, I’m looking at a two volume set called American Beetles that is new to my bookshelf. Someday I’ll have time to open them and look inside.


  1. Yes - cedar beetle.

    Habitat also distinguishes shellbark from shagbark; the former preferring moister lowland species habitats, while the latter is more fond of drier uplands. Both have my favorite bark of any eastern North American tree (out west it would be the fibrous, deeply furrowed, reddish-brown bark of incense cedar).

  2. Thanks for the confirmation on the beetle, Ted.

  3. The weevil larvae always makes me squirm when I come up the squiggly critters while I'm cracking hickory nuts. Do you think they excrete some kind of chemical to help the bore through the hard-as-rock nut shells?

    In Richland County the shagbarks were extremely productive this year. I have a cache of hickory nuts. I'll be cracking them all winter. I even left some for the squirrels.

    The nuts in the few shellbarks I found were shriveled up. That's okay. They are too hard to crack anyway.

  4. Thanks for all of your information. I gathered hickory nuts for the first time, and am looking forward to some yummy treats.