66 HISTORY OF BRITISH PERNS. 



known from all other indigenous Ferns, excepting the Ce- 

 terach, which latter is readily distinguished from them by 

 having the back of its fronds coated with brown scales, 

 among which the sori are hidden. They are the types of 

 the tribe A-Spleniece, which consists of Ferns having the 

 elongate masses of fructification attached along the side of 

 the veins, and covered by an indusium of the same elongated 

 form as the sori themselves. The Aspleniums are known 

 from their nearest allies, the Atliyriums, by the latter having 

 the free margin of the indusium fringed with capillary or 

 hair-like segments, while the margin of the indusium of As- 

 plenium is either quite entire or very slightly jagged. There 

 are nine species of Asplenlum indigenous to Britain, and all 

 of them are interesting to the cultivators of Ferns. 



The word Asplenium comes from the Greek asplenon ; a 

 name applied by old authors to some kind of Fern possessed 

 of supposed virtues in curing diseases of the spleen. 



ASPLENIUM ADIANTUM-NIGRUM, Linnceus. The Black 

 Spleenwort. (Plate XII. fig. 2.) 



This is a rather common evergreen Fern, and a very con- 

 spicuous ornament of the situations where it occurs in a 

 vigorous state. The fronds grow in tufts, and vary much 

 in size, from a height of three or four inches when it occurs 



