NEPHRODIUM. 



497 



colour above and paler beneath, those of N. spinulosum.^ seldom more than 

 l^ft. long and Sin. broad, are of a delicate light green colour on both sides 

 and perfectly flat. Further, in N. dilatatum the pinnules (leafits) and their 

 sub-divisions are usually more or less twisted or contorted. 



From the above comparisons it will at once be seen that great outward 

 diiferences exist betw^een the two plants, which, we contend, should remain 

 totally distinct, especially w^hen w^e take into consideration the fact that 

 N. dilatatum, is an extremely variable Fern, differing in form and stature 

 according to the situation in which it grows. Thus, w^hen found in a spot 

 which is wet in the spring and dried up in the summer, as on the margin 

 of a pond, its fronds are large, quite drooping, and of a peculiar dark colour. 

 A dry and rocky or a confined situation renders the fronds smaller and less 

 divided, their pinnules (leafits) being then blunt, deflexed, or drooping ; 

 whereas permanent wet will elongate the fronds and separate the leaflets and 

 also their divisions. The fructification is abundant, the sori (spore masses) 

 being situated nearer the midvein than the edge (Fig. 120) ; at first they 

 are swollen and kidney-shaped, but the indusium (covering), when bursting, 

 becomes circular, with a deep cut or depression in its lower side. — Loioe, 

 Our Native Ferns, i., t. 32 ; Ferns British and Exotic, vi., t. 27. Correvon, 

 Les Fougeres Bustiques, p. 140. 



N. dilatatum is not only distributed over all parts of Europe (wdiere its 

 existence is recorded from Lapland to Portugal and Spain), but it is dispersed 

 through the whole world : thus, it is found in Asia, in Kamtschatka ; in 

 Africa, in the Azores ; in America, in Canada and on the Rocky Mountains ; 

 whereas in England it is so common that no locality need be specified. On 

 account of its decorative qualities as well as for its hardihood, it must be 

 acknowledged as one of the most valuable Ferns known for the adornment 

 of the rockery or the shrubbery, as it grows very well upon elevated positions 

 and in exposed situations, although it wall attain greater size and beauty when 

 accorded a shady spot than when growai in full exposure to light. It is, 

 therefore, well adapted for the shaded side or base of the rockery, and as it 

 will, when once established in a favourable position, attain large dimensions, 

 forethought wall be required in planting, so that it may not smother the 

 smaller-growdng species. If grown as a pot-plant, N. dilatatum must be 

 allowed a moderate space for its roots, and it prefers a compost of fibrous 



VOL. II, 2 K 



