Mat-forming Melin's grass

Plants becoming terrestrial. Rootstock horizontally elongate, mat-forming, often proliferous. Leaves deciduous to nearly evergreen, bright green, pale toward base, distichously arranged, to 4 cm, pliant, gradually tapering to tip. Velum covering entire sporangium. Sporangium wall unpigmented. Megaspores dark gray, 275--370 μm diam., tuberculate with low and distinct tubercules; girdle obscure. Microspores brown in mass, 26--33 μm, spinulose. 2n = 22.

Spores mature late winter and spring. Shallow pools on granite outcrops; of conservation concern; Ga.

Isoëtes tegetiformans is a unique mat-forming quillwort distinguished by its distichous leaf arrangement, horizontally elongate rootstock, and nondichotomous roots. (See discussion under I. melanospora.)