Sunday, April 27, 2008

The Hop Hornbeam

A small tree has been growing in a flower bed on the southeast side of our house for ten years or so. Bearing lanceolate leaves with serrated margins, it appeared to be a type of elm, though its identity remained uncertain. This month, for the first time, the tree developed copious, dangling, olive-yellow catkins and, searching through my tree guide, I learned that it is an eastern hop hornbeam.

Members of the birch and alder family, these trees are often call "ironwoods," due to their heavy and very hard wood. Though now cultivated for ornamental plantings, hop hornbeams were once used to produce tool handles, wooden spokes, fence posts and oxen yokes (hence the hornbeam title); the "hop" designation refers to the appearance of their clustered seed pods, which resemble the plant component used for beer production. Eastern hop hornbeams are widely distributed across southeastern Canada and the eastern half of the U.S. but are generally found alone or in small stands; in fact, they are relatively small (usually 30 feet) and grow in the understory or along woodland margins. Their seeds, blown about by the autumn wind, are eaten by quail, grouse and small mammals.

Eastern hop hornbeams are tolerant of dry soils and often grow in cool, shaded areas. Indeed, the tree's only close relative in North America is the Knowlton hop hornbeam, which is found in canyons of the Southwest.