5. Isoetes Saccharata Engelm. Sugary Quill-Wort

Fig. 122

Isoetes saccharata Engelm. in A. Gray, Man. Ed. 5, 676.

1867.

Amphibious or uliginous with a flat depressed trunk. Leaves 10-30, green, pale at the base, spreading, 2'-3' long, quadrangular, bearing numerous stomata; sporange oblong, unspotted, with a narrow velum covering only one-fourth or one-third of its surface; peripheral bast-bundles wanting; ligule triangular, rather short; macrospores 420-510 μ in diameter, with very minute distinct or rarely confluent warts as if sprinkled with grains of sugar; microspores sparingly papillose, 22-30 μ long.

In mud overflowed by the tides, eastern Maryland and District of Columbia.

6. Isoetes Riparia Engelm. Riverbank Ouillwort

Fig. 123

Isoetes riparia Engelm.; A. Br. Flora, 29: 178. 1846.

Amphibious or uliginous, usually emersed when mature; leaves 10-30, green, rather rigid, 4'-8' long, quadrangular, bearing numerous stomata; peripheral bast-bundles wanting; ligule rather short, triangular; sporange mostly oblong, distinctly spotted with groups of brown cells, one-fourth to three-fourths covered with the velum; macrospores 450-756 μ in diameter, marked with distinct or anastomosing jagged crests or somewhat reticulate on the lower side; microspores 28-32 μ long, more or less tuberculate.

Borders of the lower Delaware River.

7. Isoetes Foveolata A. A. Eaton. Pitted Ouillwort

Fig. 124

Isoetes foveolata A. A. Eaton; Dodge, Ferns and Fern Allies of New Eng. 38. 1896.

Isoetes foveolata pleurospora A. A. Eaton, Rhodora 5: 280. 1903.

Amphibious from a bilobed or rarely trilobed base. Leaves 15-70, stout, 2'-6' long, pinkish even when dry, or rarely dark green; stomata scattered, found only near the tips; no peripheral bast-bundles; monoicous or becoming dioicous; velum covering 1/4 or 1/3 of the sporange; ligule round-ovate; sporanges thickly sprinkled with dark cells which are often collected in groups; macrospores 380-560 μ. covered beneath with very thick-walled reticulations, the openings appearing like little pits; reticulations elongate on the upper surface of the spore; microspores dark brown, 22-35 μ long, densely reticulate and usually slightly papillose.

In muddy banks, New Hampshire, Massachusetts and Connecticut.

8. Isoetes Eatoni Dodge. Eaton's Quillwort

Fig. 125

Isoetes Eatoni Dodge, Ferns and Fern Allies of New Eng. 39. 1896.

Amphibious from a large trunk 1/2- 1 1/4' in diameter. Leaves of the submerged plant 30-200, varying in length up to 28', marked with an elevated ridge on the ventral side; leaves of the emersed plant shorter, 3-6; stomata abundant; peripheral bast-bundles irregular in occurrence or often wanting; velum covering 1/4 of the sporange, polygamous; sporanges large, 0.4' by 0.15', pale spotted; macrospores small, 300-450 μ in diameter, marked with convolute labyrinthine ridges and cristate on the angles of the inner face; microspores 25-30 μ in diameter, minutely tuberculate.

In mud flats, New Hampshire to New Jersey.