GENUS i. 



QUILLWORT FAMILY. 



53 



A, 



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 A'-i-l' 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 

 i of the sporange, polygamous; sporanges 

 large, 0.4' by 0.15', pale spotted; macrospores 

 small, 300-450 /" in diameter, marked with con- 

 volute labyrinthine ridges and cristate on the 

 angles of the inner face; microspores 25-30 ^ 

 in diameter, minutely tuberculate. 



In mud flats, New Hampshire to New Jersey. 



9. Isoetes Dodgei A. A. Eaton. Dodge's 

 Quillwort. Fig. 126. 



Isoetes Dodgei A. A. Eaton, Fern Bull. 6 : 6. 1898. 

 Isoetes canadcnsis A. A. Eaton, Proc. U. S. Nat. 

 Mus. 23 : 650. 1901. 



Plant amphibious from a bilobed trunk. 

 Leaves 10-75, 8'-i8' long when submersed, 

 erect, or spirally ascending when scattered ; 

 emersed leaves 4-6' long, tortuous and often 

 interlaced, with numerous stomata and usually 

 4 bast-bundles ; velum narrow, covering i to i 

 of the sporange; sporanges thickly sprinkled 

 with light brown cells ; macrospores more 

 numerous on submersed plants, globose, 500- 

 675 / in diameter, sparsely covered with ir- 

 regular crests which at maturity separate into 

 irregular groups leaving bare spaces, serrate 

 or spinulose at the top ; microspores more 

 numerous on emersed plants, 22-44 P, ashy, 

 papillose or wrinkled. 



Growing in mud flats, East Kingston, New 

 Hampshire. 



10. Isoetes Engelmanni A. Br. Engelmann's 



Quillwort. 



Fig. 127. 



Isoetes Engelmanni A. Br. Flora, 29: 178. 1846. 

 Isoetes Engelmanni fontana A. A. Eaton, Fern Bull. 13: 



52. 1905. 

 Isoetes Engelmanni gracilis Engelm. in A. Gray, Man. 



Ed. 5, 677. 1867. 

 Isoetes Engelmanni valid a Engelm. in A. Gray, Man. 



Ed. 5. 677- 1867. 



Amphibious, usually partly emersed when mature. 

 Leaves 25-100, light green, quadrangular, tapering, 

 9'-2o' long, bearing abundant stomata ; peripheral 

 bast-bundles present ; monoecious ; sporange oblong 

 or linear-oblong, unspotted; velum narrow; macro- 

 spores 320-750 i". in diameter, covered with honey- 

 comb-like reticulations; microspores 24-30^ long, 

 mostly smooth. 



In ponds and ditches, rooting in mud, Maine to Vir- 

 ginia and Pennsylvania, Illinois and Missouri. 



