Appalachian-Blue Ridge forests hickories ("Carya" spp.), red maple ("Acer rubrum"), sugar maple ("Acer saccharum"), white ash ("Fraxinus americana"), tulip tree ("Liriodendron tulipifera"), American beech ("Fagus grandifolia"), black cherry ("Prunus serotina"), black birch ("Betula lenta"), black tupelo ("Nyssa sylvatica"), and American elm ("Ulmus americana"). Flowering dogwood ("Cornus florida") is a common understory tree. Central Appalachian pine-oak rocky woodlands occur on lower-elevation hilltops, outcrops, and rocky slopes and have a patchy or open aspect. Pitch pine ("Pinus rigida") and Virginia pine ("Pinus virginiana") are common within their respective ranges. These pines are often mixed with dry-site oaks such as chestnut oak ("Quercus prinus"), bear oak
Dioscorea sylvatica variable species, with several extremely distinct varieties. It is threatened from illegal collecting for traditional medicine, as well as for the horticultural trade. As a consequence it is listed as Vulnerable. Dioscorea sylvatica Dioscorea sylvatica ("forest elephants foot") is a species of a twining tuberous vine that is native to Africa. It is common and widespread in forest and thicket, throughout the summer rainfall areas of East and Southern Africa. It produces a distinctively flattened caudex, often with lobes that spread out. The creeping shoots grow throughout most of the year, though each will periodically die back and be replaced