244 THE AMPHIBIOUS QUILLWORTS. 



able for having very dark grey, almost black, niega- 

 sporcs, being unique in this respect among the species of 

 eastern America. It is also one of the few species in 

 which the indusium completely covers the sporangium. 

 This species has from five to ten tapering, slender 

 leaves about two inches long. The sporangia are rather 

 roundish, and the megasporesare from 

 35O/" to 450 u in diameter. The surface 

 is marked by many slight projections 

 that are roundish or confluent, form- 

 ing low, short, scale-like crests. The 

 microspores are smooth or slightly 

 Megasporeof papillose. The plant has been found 



Isoetes melanospora. . . . . 



in several localities, but never outside 

 of Georgia. It is so different from the other species of 

 the East that identification will be easy, even for the 

 beginner. 



Isoetes Flaccida. 



The only species of quillwort with which the State of 

 Florida is credited is the one bearing the name of Isoetes 

 flaccida. In general appearance it is like all the am- 

 phibious quillworts, but the' spore-char- 

 acters are unlike any others of our 

 region, being more closely related to vari- 

 ous tropical species. This difference, and 

 the limited area it inhabits, make it an- 

 other species easily identified by the 



, . Megaspore of 



begi n n e r. /*, jiacdda. 



The leaves are from ten to thirty-five in number, and 

 from three inches to two feet long. The plant usually 

 roots beneath the water, and the long leaves float on the 



