A taxonomic revision of granite outcrop species of Minuartia (Arenaria)

Minuartia glabra (Michx.) Mattfeld andM. uniflora (Walt.) Mattfeld are proposed as the proper taxonomic treatments ofArenaria glabra Michx. A. groenlandica var.glabra (Michx.) Fern.] andArenaria uniflora (Walt.) Muhl. respectively. A previously unreported species,Minuartia alabamensis is described as new.Minuartia alabamensis andM. uniflora axe more closely related to one another than either is toM. glabra. Minuartia glabra is postulated to be derived from the Arcto-Tertiary flora, which invaded the Piedmont from the Appalachian Highlands.Minuartia alabamensis andM. uniflora are thought to be relicts or species derived from the Madro-Tertiary flora, which invaded the Piedmont from the Southwestern United States and Mexican Highlands.