28 



POLYPODIACEAE 



1. N. exaltata (L.) Schott. Eootstock stoutish, often 

 nearly erect: leaves erect or spreading in all directions, 

 2.5 m. long or less; petioles 

 rather slender, mostly brown, 

 more or less scaly; blades 

 elongate-linear in outline, 

 often narrowly so: leaflets 

 numerous, 3^6 cm. long, the 

 blades lanceolate to elliptic- 

 lanceolate, singly serrate or 

 singly crenate, or with some 

 of the teeth occasionally ac- 

 companied with smaller teeth, 

 coarsely and sparingly pu- 

 bescent beneath, subcordate 

 to truncate at the base, the 

 lower side rounded, the up- 

 per auricled: indusia reni- 

 form: sori less than 1.5 mm. 

 in diameter. (BOSTON- 

 FERN.) Hammocks. Fig- 

 ure 16, reduced. 



This, the Boston-fern, is 

 sometimes locally known by 

 the name of Sword-fern. It grows in all the hammocks 

 and- in all kinds of hammocks. It grows on trees, in 

 humus on the hammock floor, and in the honeycombed 

 sides of small and large lime-sinks. It is scattered 

 throughout Royal Palm Hammock, as single plants, small 

 colonies, and as extensive beds. Although common in 

 dense shade, this plant reaches its best development in 

 open sunny spots in hammocks and there sometimes 

 covers the floor to the exclusion of nearly all other vege- 

 tation. As in the case of the following species, the 

 petioles of the leaves are favorite supports for some 

 species of mosses and liverworts. This fern was discov- 



