1922] 



PFEIFFER — MONOGRAPH OF THE ISOETACEAE 137 



man? (Mo. Bot. Gard. Herb.) ; lakelet of clear limestone 

 water near Marianna, August, 1850, Chapman (Mo. Bot. 

 Gard. Herb.) ; marshes, Apalachicola, 1890, Herb. Chapman 

 (U. S. Nat. Herb.); Manatee, April, 1878, Garber without 

 number (Mo. Bot. Gard. Herb, and U. S. Nat. Herb.) ; same 

 place and date, Garber 2312 (Mo. Bot. Gard. Herb, and U. S. 

 Nat. Herb.) ; same, Garber 32 (U. S. Nat. Herb., N. Y. Bot. 

 Gard. Herb., and Gray Herb.) ; open miry places in Turnbull 

 Swamp, Halifax River, May, Curtiss 3813 (U. S. Nat. 

 Herb.); Lake Flirt, August, 1878, Garber (Mo. Bot. Gard. 

 Herb.). 



31a. Var. alata (Small) Pfeiffer, var. nov. 



/. alata Small, Ferns of Florida, 133. 1918. 



Similar to the species in stature and leaf characters, but dif- 

 fering in spore markings; upper faces usually crowded with 

 tubercles, which may become ridge-like; lower face with bold 

 rounded ridges so anastomosing as to give more or less irregu- 

 larly reticulate effect ; spore range is about the same, 290-540 m 

 as extremes, with 430-540 u most commonly occurring. A form 

 in which the megaspores are usually larger (430-540 (j) and the 

 microspores in the higher range of 30-33 \x, then showing spines 

 quite readily, might be distinguished {Eaton 832 and 337, Curtiss 

 3813, Mo. Bot. Gard. Herb.). 



Distribution: Georgia, Florida. 



Specimens examined: 



Georgia: in sluggish pine-barren stream, Bulloch Co., partly 



emersed, 10 June, 1901, Harper 84-3 (U. S. Nat. Herb.); in 

 sluggish pine-barren stream, partly emersed, Bulloch Co., 

 26 June, 1901, Harper 951 (Mo. Bot. Gard. Herb., U. S. Nat. 

 Herb., Gray Herb., and N. Y. Bot. Gard. Herb.); in cypress 

 pond near Cobb, Sumter Co., 11 July, 1901, Harper 10^6 

 (Mo. Bot. Gard. Herb., Gray Herb., U. S. Nat. Herb., and 

 N. Y. Bot. Gard. Herb.). 



Florida: open miry places in Turnbull Swamp, Halifax River, 



May, Curtiss 3813 (Mo Bot. Gard. Herb.) ; margin of shaded 

 pond, Riverland, Sumteit Co., 23 July, 1900, Curtiss 6696 

 (Mo. Bot. Gard. Herb, and N. Y. Bot. Gard. Herb.) ; Miami 

 River and Everglades, Dade Co., 17 November, 1903, Eaton 



