THE WALKING FERN AND HARTS-TONGUE. 267 



and Kansas. It was once regarded as being 

 closely restricted to limestone rocks, and, 

 indeed, shows a preference for them, growing 

 where the soil is soft and thin and its roots 

 can come in contact with the stone ; but it is 

 now known to grow also upon sandstone, 

 shale, gneiss, quartzite and granite. The 

 books unite in calling it a rare species but 

 this is due more to its local distribu- 

 tion than to any lack of the plants 

 themselves. It certainly is not rare 

 with the rareness of the hart's-tongue 

 or Asplenium ebenoides or even the lit- 

 tle curly grass. On the dryish ledges 

 of shaded cliffs it frequently spreads a 

 carpet of its interlacing fronds that 

 may be pulled off in lar^e sheets. Its 

 fondness for horizontal shelves and the 

 tops of rocks is especially noticeable. 

 Miss S. F. Price notes in the Fern Bul- 

 letin that in parts of Kentucky the 

 plant is called wall link. 



The leathery, dark green and glossy 

 fronds endure the winter unharmed and 

 last for some time the following year. 

 There is some belief that they may occa- 

 sionally last through two winters. On ac- 

 count of its interesting features, it is a 

 desirable plant for the fern garden. It 

 will grow and thrive in any garden soil if 

 given deep shade, but it does much better 

 in the chinks of a rockery made of lime- 

 stone or other calcareous material. 



A FRUITING 

 FROND. 



