Cove forests occur in coves and on low north- and east-facing slopes in the southern Blue Ridge and central Appalachian Mountains. They are among the most biologically diverse ecosystems in the country. Typical trees of these forests are sugar maple (Acer saccharum), American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), Carolina silverbell (Halesia tetraptera), tulip poplar (Liriodendron tulipifera), red maple (Acer rubrum), white oak (Quercus alba), northern red oak (Quercus rubra), yellow birch (Betula alleghaniensis), yellow buckeye (Aesculus flava), and basswood (Tilia americana). Oaks gain numbers on drier sites.