20 WAYSIDE AND WOODLAND FERNS. 



Trichomanes radicans grows yearly more rare at Killarney, 

 and probably no more plentiful in private collections. We beg 

 our readers to help in the work of preserving the indigenous 

 flora of the British Islands by abstaining from such practices. 

 If it is desired to grow such a difficult species, and the necessary 

 contrivances are available, specimens brought from the Canaries, 

 the Azores or Madeira, where the fern grows abundantly, are 

 quite as good for the purpose, and can be obtained for a trifle 

 from the florists. 



The Killarney Fern has a slender wiry rootstock, which runs 

 along the lower surfaces of wet rocks, often to a length of two 

 or three feet, and is densely clothed in dark bristle-like scales. 

 Where the growth is luxuriant these rootstocks form a net- 

 work by their branching and crossing, and their delicate and 

 abundant rootlets cling closely to the rock in all directions. 

 At intervals the fronds arise singly from the rootstock, and 

 usually assume a drooping or inverted position. The stipes, or 

 stalk portion, is winged along each side, except towards the 

 base. The rachis, or midrib, is also winged, and in truth the 

 whole of the leafy portion is merely the translucent wing of 

 the rachis continued round its stiff, wire-like branches and their 

 further divisions. The frond as a whole may be described as 

 three or four times pinnately divided, and wedge-shaped, from 

 six to eighteen inches long of which one-third is the length of 

 the stipes and two-thirds the rachis. Although apparently so 

 fragile, the fronds are of a more permanent character than 

 most of our native ferns, subsisting for several years, and 

 coming to their full development very slowly. 



The character that separates the Bristle-ferns from the Filmy- 

 ferns is afforded by the indusium, which is not divided into two 

 valves as in Hymenophyllum, but undivided and cup-shaped. 

 It is produced by an expansion of the translucent tissue of 

 the frond round an extension of one of the nerve branches. 

 This forms the receptacle upon which the sporanges are 



