POLYPODIACEAE 



29 



ered in Florida about the middle of the last century. 

 It ranges northward in Florida to the lake region, and 

 is distributed on the mainland and islands of tropical 

 America. 



2. N. biserrata (Sw.) Schott. Eootstock stout, often 

 erect: leaves erect, spreading, or reclining, 1-5 m. long 

 or more ; petiole stout, 

 more or less scaly at 

 the base, usually 

 brown; blade broadly 

 linear in outline, or 

 narrowly so when 

 greatly elongate: leaf- 

 lets numerous, mostly 

 1-2 dm. long, the 

 blades lanceolate to 

 linear-lanceolate, dou- 

 bly serrate or doubly 

 crenate, finely and 

 closely pubescent be- 

 neath, truncate to 

 broadly cuneate at 

 the base, the lower 

 side of the base 

 rounded, the upper 

 side slightly angled : 

 indusia suborbicular : 

 sori fully 1.5 mm. in 

 diameter. (SWORD- 

 FERN.) Hammocks. Figure 17, reduced. 



This, the Sword-fern, is sometimes locally known by 

 the name of Boston-fern. Like the preceding species 

 it grows in all the different kinds of hammocks and 

 usually in company with its close relative, the preceding 

 species. It occurs throughout Eoyal Palm Hammock, 

 but in places favorable to its growth it reaches an ex- 

 traordinary development. Although it is sometimes epi- 



