Hardwood trees. Computer illustration of a selection of trees classified as hardwoods, or broad-leaved. Clockwise from top left: beech (Fagus sp.), ash (Fraxinus sp.), maple (Acer sp.), lime (Tilia sp.), oak (Quercus sp.), birch (Betula sp.), chestnut (Castanea sp.), rowan (Sorbus sp.). Hardwoods are angiosperm trees that reproduce by flowers and have broad leaves. They are distinguished from softwoods by the presence of pores, or vessels, in the wood tissue.