BORDER SPECIES. 



287 



grow in tufts from a small rootstock. They have dark, 

 shining stipes and rachids and are three or four times 

 pinnate. The blades are triangular ovate and the pinnae 

 ovate and mostly stalked. The ultimate pinnules are 

 very small and covered beneath with a whitish 

 waxy powder. This powder or farina is very 

 common in other species of this group and ap- 

 pears to serve as a protection from too great an 

 evaporation of moisture, since the species pos- 

 sessing it are all inhabitants of dry and sunny 

 places. The sporangia are without indusium 

 and are borne in lines near the margins of the 

 pinnules by which they are commonly half 

 enfolded when young. The generic name 

 Notholcena is derived from two words mean- 

 ing a spurious cloak. By some this is be- 

 lieved to refer to the rudimentary indusia ; 

 by others to the woolly covering of the 

 original species. From the generic name is 

 derived the common name of cloak fern, 

 occasionally applied to this species. An 

 illustration of a fruited pinnule will be found 

 in the Key. 



The Killarney Fern. 



The group to which the Killarney 

 fern (Trichomanes radicans) belongs, dif- 

 fers from our common ferns in their 

 manner of fruiting as well as in a few 

 other matters, and botanists have there- 

 fore placed them in a separate order as KILLARNEY FERN. 



i T T 111 i t . Trichomanes radicans. 



the Hymenophyllaceas, equal m rank to 



