HARD FERN. 31 



the latter appear crowded together. They are comparatively 

 thick, leathery, glossy on the upper surface, and evergreen ; 

 pale beneath. The fertile fronds are twice the length of the 

 barren, pinnate throughout, with wide spaces between the 

 pinnae, which are narrowed by having their margins rolled over 

 the sori. The sori form a continuous line near the margin 

 from which the indusium springs (Plate 4). The lower pinnas 

 are extremely short and distant, but the upper ones are long 

 and curved. Owing to this attenuation of the pinnae the fertile 

 frond presents a strong likeness to the backbone of a fish, and 

 it seems surprising that it has not been called the Fishbone 

 Fern.* The polished brown stipes is, in both forms, slightly 

 furnished with brown scales near the base. The fertile fronds 

 perish after the spores have been distributed in autumn. 



Owing to the evergreen nature of the barren fronds, the Hard 

 Fern is more noticeable in winter, when few other species are 

 to be seen. Then on stony moorlands we may find it in 

 abundance. In pine-woods on the greensand hills in Surrey 

 we have found it covering acres of ground, the plants growing 

 so closely together that their rootstocks were entangled, and it 

 was difficult to detach a single specimen from the mass. Some 

 of the most luxuriant specimens we have seen were at Wood- 

 stock, Co. Kilkenny. Excavations had been made here and 

 there in the sloping bank to get stone for mending that beautiful 

 woodland road beside the river Nore ; and the Hard Fern had 

 taken possession of the recesses so left, and had covered their 

 walls with drooping barren fronds from amidst which the fertile 

 fronds of great length towered aloft. It reaches its highest 

 development on a sloping bank where its roots can obtain 

 abundant free moisture, and its fronds be bathed occasionally 

 in mists (Plates 26, 27). 



It is found throughout the British Isles from Shetland to 

 Jersey and Guernsey, from sea-level to an elevation of 4000 



In Cumberland it is known as Herrin'-bone Fern. 



D 



