6 OUR NATIVE FERNS AND THEIR ALLIES 



(Camptosorns), the rare hart's-tongue (Scolopendrium)* and 

 many of the smaller spleenworts. The long, pendent fronds 

 of Cystopteris bulbifera add greatly to the beauty of out- 

 natural ravines, and often serve to conceal the uncouth 

 rocks, or at least draw the attention to that which is more deli- 

 cate and artistic. On dripping rocks, or where the sides of 

 ravines are kept continually moist by the spray of waterfalls, 

 such delicate pellucid ferns as the filmy-fern (Trichomanes) and 

 Pellcsa gracilis 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. Cystopteris in some- 

 what drier situations is thinly herbaceous, while Asplenium 

 Trichomanes w\& Camptosorus, 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 (Nothclcena), the lip-ferns (Cheilanthes), 

 and the cliff-brakes (Pellcsa). 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 thaltctroidcs found in Southern Florida, 

 though Acrostichum aureuin 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, especially P. incanum, P. Scouleri, and P. aureum, the 

 last always being associated with the cabbage-palmetto (Sabal 

 palmetto). Vittaria, Tanitis, and Nephrolepis are also of this 

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

 occasionally found on other tree-trunks. Ophioglossum pal- 

 matum, 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. 



