It forms one of the great floral provinces of the Earth. There are the trees that bear luxuriant bloom, such as serviceberry, redbud, hawthorne, tulip poplar, dogwood, locus, sourwood, and many others. Among the numerous shrubs with particularly showy flowers are the rhododendron, azalea, and mountain laurel. Roan Mountain in the North Carolina-Tennessee Unakas is one of the most extensive of these, with some 1,200 acres of natural gardens sprawling vivid rose and pink and purple rhododendron across its high pinnacle and down its slopes. It is estimated that of some 2,000 species of Appalachian flora, perhaps 200 are native to and wholly confined to the Southern Appalachians.
Cove forests are the most diverse habitats in the Southern Appalachians.
The coves thrive in the mountain areas where Ocoee series rocks have overlaid younger limestone rocks. The limestone, as parent material, provided rich soils to support the floristic diversity of cove forests as well as agriculture in the 19th century. Coves are very moist and rarely suffer even brief drought. The tulip poplar and hemlock often are the largest trees in a cove forest, but the coves usually contain at least twice as many species as any other eastern woodland. The biodiversity of the Southern Appalachians is unrivaled in the eastern United States.