6 OUR NATIVE FERNS AND THEIR ALLIES. 



tosorus), the rare hart's-tongue (Phyllitis)* and many of the 

 smaller spleenworts. The long, pendent fronds of our Filix 

 bulbifera add greatly to the beauty of our natural ravines, and 

 often serve to conceal the uncouth rocks, or at least draw the 

 attention to that which is more delicate and artistic. On 

 dripping rocks, or where the sides of ravines are kept con- 

 tinually moist by the spray of waterfalls, such delicate pellucid 

 ferns as the filmy-fern (JTrickomanes) and one Cryptogramma 

 may be sought. There seems to be a direct connection between 

 the environment and the texture of the fern. The last two 

 mentioned grow in very damp situations, and are pellucid and 

 almost membranous. The Filix in somewhat drier situations 

 is thinly herbaceous, while Asplenium trichomanes and Camp- 

 tosorus, requiring less moisture, are more firm, and form the 

 transition to the next group. 



1 6. On dry cliffs we may look for the various species of 

 Woodsia, the cloak-ferns (Notholcena), the lip-ferns (Chetlanthes), 

 and the cliff-brakes (Pellcea). Many of these are firm and even 

 leathery in texture, and others are thickly covered on one or 

 both sides with tangled hair or scales, fitting them to survive 

 long periods of drought. 



1 7. Only one of our native species is strictly aquatic, the 

 anomalous Ceratopteris thalictroidcs found in Southern Florida, 

 though Acrostichuin aureum is often found with its rhizoma 

 rising from the water of salt marshes. Osmunda regalis is oc- 

 casionally found in standing water several inches deep, though 

 this is not usual. 



1 8. Among the epiphytic ferns are several species of Poly- 

 podium, P. polypodioides, P. Scouleri, and Phlebodium, the last 

 always being associated with the cabbage-palmetto (Sabal pal- 

 metto). Vittaria, Cheilogramma, and Nephrolepis are also of 

 this class, and are frequently pendent from the same plant, 

 though occasionally found on other tree-trunks. Cheiroglossa 

 palmata, another peculiar tropical fern-ally, belongs to the same 



* This rare fern seems to show a decided preference for limestone rocks, 

 and thus far has been found only above the geological formation known as 

 the Corniferous limestone. I believe a thorough search for this fern along 

 the outcrops of the formation in Central New York and elsewhere would show 

 a wider distribution than is at present attributed to this species. 



