88 FERNS THEIR NATURE AND CLASSES [CH. 



and feathery beauty of fronds give them a charm all 

 their own. P. divisilobum robustum is, perhaps, the 

 most beautiful of all Ferns in cultivation. 



The Scale Fern (Ceterach officinarum] will only thrive 

 properly on a wall or in a soil chiefly composed of old 

 decayed lime-stone, but in such conditions its very 

 marked character may be seen to perfection. 



The Spleenworts are nearly all small evergreens, 

 and interesting to collectors, though some are trouble- 

 some to grow in the open air. 



The Prince of Wales' Plume (Struthiopteris germanica) 

 is a beautiful, strong-growing plant, with a habit of its 

 own ; so is the Onoclea sensibilis. Both these are quite 

 hardy, though not indigenous to Britain. 



The Hartstongue (Scolopendrium) is the hardiest and 

 best known of all our native Ferns. It has broken from 

 the type into almost innumerable forms and varieties, 

 all interesting, some striking and beautiful. The sports 

 of Hartstongue are said to number from five hundred 

 to nine hundred varieties, many of them mere " vegetable 

 cripples" not worth cultivating. Crispum is the best 

 of about eighty of the named varieties ; its margin is 

 frilled from the base to the point. 



Of those British Ferns which are best suited to a 

 cool house under glass, I would suggest the following 

 amongst many. 



