82 FEENS OP GREAT BRITAIN. 



tined to grow on rocks, it has tough wiry stems, which 

 penetrate into clefts, and hold the plant so firmly there 

 that it is difiicult of eradication. The rhizome is short, 

 and the fronds often grow from it in tufts. The vein- 

 ing may be usually readily seen. Each pinna has a 

 mid-vein, which gives off lateral veins, these again 

 sending off others. The clusters of capsules lie on that 

 side of the lateral veins which is nearest the upper part 

 of the pinnule, forming bright rust-coloured Hues, often 

 of an oblong form. These are covered by an indu- 

 sium, which bursts open as they ripen. 



A Sea Spleenwort, called AspUnium difdrme, very 

 much resembling our native species, is found on the 

 rocky coasts of New Holland. Mr. Backhouse remarks 

 of this plant : — " It becomes more narrow when growing 

 further from the sea, and the leaves become more divided, 

 and are separated iato such narrow segments, that the 

 lines of fructification are thrown upon their margins; 

 it then becomes Cmnqpteris odontitis, but every possible 

 gradation is to be met with between this state and that 

 in which it grows on rocks washed by the sea." 



8. A. viride (Green Spleenwort). — Fronds linear, pin- 

 nate; pinncB alternate, roundish, egg-shaped, wedge- 

 shaped at the base, bluntly serrated. This very pretty 

 little fern varies much in size, according to the situation 

 on which it grows. It is so like the Common Wall 

 Spleenwort that it might at first be mistaken for it, but 

 it may be distingmshed by the colour of its slender 

 rachis, which is green, while the stalk of the Wall 

 Spleenwort is throughout of a purplish-black, and by 

 the rounded notches on the margins of its leaf-like 



