Any of numerous trees and shrubs, found worldwide, that have exceptionally tough or hard wood useful for timber, fence posts, and tool handles.
Species include the eastern, or American, hop hornbeam ( Ostrya virginiana ), a small tree of northern Iran ( Parrotia persica ), and Ceylon ironwood ( Mesua ferrea ). Though these trees belong to different plant orders, all have bright yellow to orange and scarlet autumn foliage.