19 W] The Land of Ferns 103 



hanging rocks with rather smooth faces the plants are often scattered. 

 Most of the kinds grow not only on the perpendicular faces of the 

 rocks, but also on the top of boulders and all more or less horizontal 

 surfaces. The masses of leaves of all sizes and kinds of ferns often 

 completely hide numerous pitfalls of various sizes and ranging from 

 a few feet to twelve feet deep. Walking is rendered exceedingly 

 dangerous from these treacherous pitfalls alone, not to mention the 

 soft and crumbling edges of cliffs and ledges, i- 



Among the tropical ferns that do not comply with our rule of these 

 three tropical phytogeographic areas, are the amphibious leather-ferns 

 (Acrostichiun) , which extend northward along the coastal strip or 

 through the Everglades up into the Lake region, the floating-ferns 

 (Ceratopteris) which are scattered through the peninsula up into the 

 Lake region, and such epiphytes as the hand-fern (Cheiroglossa) , the 

 serpent-fern (Fhlehodium), the vine-fern {Phymatodes), the shoe- 

 string fern (Vittaria), two species of strap-fern {CaitipyJoneuriwi), 

 and the sword-fern {Nephrolepis). 



The exception in the ease of the epiphytes, however, is easily ac- 

 counted for. The soil or rock conditions in the country lying between 

 southern Florida and the northern part of the peninsula are wanting, 

 but whenever the conditions of hammocks in this intervening territory 

 are favorable, for example, the hammock on the eastern shore of 

 Okeechobee, these epiphytes, finding congenial conditions, take hold 

 and thrive. 



There are nine kinds of ferns common to the Everglade Keys and 

 to the lime-sink region. They are of tropical origin. There are forty- 

 two species growing on the Everglade Keys not yet found in the lime- 

 sink region, and five species have been collected in the lime-sink region 

 not 3'et met with on the Everglade Keys. 



Travelers and botanists observed and perhaps collectfd specimens 

 of ferns in Florida before the begiiniing of tiie Eighteenth century. 

 Then during the earlier part of the last century, further collections 

 were made in many localities, and about the middle of that century 

 nearh' fifty species of ferns were known to grow wild in the entire 

 state. During the eiglitli iiud ninth decades of the last centurv and 



" For more defnilod accounts of these fern jtrottops see A. 11. Curtiss, Plant World 

 68-70, 1902, and R. M. Harper. American Fern Journal 6: 68 81. 1016. 



