Isoëtes tegetiformans

Rury

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.
... more about "Isoëtes tegetiformans"
several +  and 1 +
W. Carl Taylor +, Neil T. Luebke +, Donald M. Britton +, R. James Hickey +  and Daniel F. Brunton +
Mat-forming Melin's grass +
alternating +
Shallow pools on granite outcrops +
pale +  and bright green +
straight +
deciduous;nearly evergreen +
recurved;erect;spreading +
tapering +
0 cm0 mm <br />0 m <br /> (4 cm40 mm <br />0.04 m <br />) +
deltate;cordiform +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +
tuberculate +
Spores mature late winter and spring. +
Ann. Missouri Bot. Gard. +
branched +  and simple +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Isoëtes tegetiformans +
Isoëtes +
species +
brown-streaked;completely brown +
ephemeral +, evergreen +  and perennial +