American Hornbeam (Carpinus caroliniana)

American Hornbeam (Carpinus caroliniana)

Plantae>Magnoliophyta>Magnoliopsida>Fagales>Betulaceae>Carpinus caroliniana Walt.

	American Hornbeam, usually called Ironwood around here, is a fairly common understory tree found mostly along streambanks. Both of the two recognized subspecies (or varieties) occur in Durham County, NC, the northern ssp. virginiana (Marsh.) Furlow and the southern ssp. caroliniana, though they are quite similar and many of the trees in Durham are intergrades. The one photographed here is a typical ssp. caroliniana - the bracts of the infructescence are more rounded and with a few blunt teeth versus ssp. virginiana's sharp tips and more, sharper teeth.
	The leaves of ssp. caroliniana are slightly smaller and narrower, with a more acute apex, and smaller and blunter secondary teeth.
	This is a typical ssp. virginiana, photographed in the mountains of Carroll Co., Virginia. The differences are subtle - note that this leaf is broader and more jaggedly toothed than the one above and the bracts are less rounded and more toothed. Hophornbeam (Ostrya virginiana) has similar leaves but much rougher bark and hop-like fruit clusters.
	Male catkins appear in early spring. Durham Co., NC 3/24/07.
	The smooth, muscular bark is unique, not similar to that of any other local tree. Durham County is in the intergrade zone between ssp. virginiana of the mountains and ssp. caroliniana of the Coastal Plain. Though many specimens are intermediate, variety caroliniana is more common here; most specimens of virginiana are from the northern part of the county.
	Bark of a large tree. Durham Co., NC 3/24/07.
	Bark of the same large tree, further down the trunk. Durham Co., NC 3/24/07.

More information:
NC State
Trees of Alabama and the Southeast
UCONN
Virginia Tech Dendrology

Revised 3/24/07 cwcook@duke.edu

All photographs and text ©2007 by Will Cook unless otherwise indicated.