Isoetes tegetiformans
 Isoetes tegetiformans commonly known as mat-forming quillwort or mat-forming Merlin's grass is an aquatic pteridophyte endemic to the U.S. State of Georgia. It grows exclusively in shallow temporary pools on granite outcrops often with only 2 cm of soil. Only 7 populations are known to exist and three of these have been destroyed since the plant's discovery in 1976.