TRICIIOiYIANES RADICANS 



257 



Unguiceps. — A narrow form of the marginate section with 

 divided tips which curve downwards like claws. 



IVardii. 



Wardii (Fig; 315). — A dense, conglomerate form, the whole plant 

 becoming a mass with no indication at all of the normal strap ; 

 the frond edges bear bulbils ; raised by Mr. Glave of Scarborough. 



TRICHOMANES RADICANS (The British Fern) 



(Plate XXXIX) 



Trichomanes radicans belongs to the small group of Filmy Ferns 

 found in Great Britain, but which are abundant in tropical and 

 subtropical Fern habitats where extremely 

 humid conditions, both of soil and atmos- 

 phere, prevail. Their fronds (Fig. 316) are 

 so thin and translucent as to be entirely 

 dependent upon such conditions for their 

 existence, since dry air shrivels them at 

 once beyond recovery. In this country T. 

 radicans has been reported as found in York- 

 shire, but in Ireland it has been found so 

 frequently as to have acquired the popular 

 name of the Killarney Fern. Its name Fig. 316. r. radicans (pinna). 



