Isoëtes tegetiformans
Ann. Missouri Bot. Gard. 68: 100. 1978.
Common names: Mat-forming Melin's grass
Treatment appears in FNA Volume 2.
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.
Phenology: Spores mature late winter and spring.
Habitat: Shallow pools on granite outcrops
Discussion
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.)
Of conservation concern.
Selected References
None.
Lower Taxa
None.