A RUNNING FERN. 



Rhipid optcris p citatum. 



By Willard N. Clute. 



In the tropics the fern collector must have a quick 

 and discriminating eye if he would recognize all of 

 the ferns. In more temperate regions we have but to 

 scan the undergrowth in the woodlands and marshes 

 and the vegetation on the cliffs to be sure of not miss- 

 ing the objects of our quest, but as we approach the 

 equator, ferns of tree-like size begin to appear and with 

 them smaller ferns in all sorts of places ; on the trunks 

 and branches of trees, among the mosses on moist 

 rocks, on old walls and even on the roofs of houses. 

 To add to the collector's confusion, many of the ferns 

 are no longer fern-like in the usual sense of that word. 

 They climb like vines up the stems of trees or over 

 lower forms of vegetation, they creep about on rocks 

 and old logs, they decrease in size almost to the vanish- 

 ing point or their fronds become so thick and leathery 

 that we may pass them by without a thought as to their 

 true character. 



One of the most curious of these species is the trail- 

 ing plant- once known as Acrostichum peltatum but 

 now usually called Rhipid optcris peltatum. I have yet 

 to find anyone who would take it for a fern at first 

 glance. It is almost exactly like our common ground 

 pine {Ly cop odium complanatum) though smaller and 

 trails over the soil in deep woodlands in much the same 

 way. Probably the first intimation one has that it is a 

 fern, is the finding of the strange little rounded fertile 

 fronds covered with sporangia on their under sides, as 

 he looks his specimen over to locate the fruiting parts. 



This plant was originally called an Acrostichum be- 



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