Virginia quillwort

Isoëtes virginica var. piedmontana N. E. Pfeiffer; I. piedmontana (N. E. Pfeiffer) C. F. Reed

Plants becoming terrestrial. Rootstock nearly globose, 2-lobed. Leaves deciduous, dull green, pale to dark brown toward base, spirally arranged, less than 30 cm, pliant, gradually tapering to tip. Velum covering less than 1/3 of sporangium. Sporangium wall brown-streaked to completely brown. Megaspores white, 400--480 μm diam., boldly tuberculate to rugulate with cristate, occasionally branched to anastomosing ridges; girdle obscure. Microspores light brown in mass, 27--33 μm, spinulose. 2n = 22, 44.

Spores mature late in spring-early summer. Mud flats and depressions on and around granite outcrops; Ala., Ga., S.C., Va.

Short plants with 15 to 50 leaves and a tendency toward lower and more open megaspore ornamentation have been called Isoëtes virginica var. piedmontana Pfeiffer.