55 



sheltered situation it seems almost, if not quite, as much at home 

 as among its native alpine rocks. 



** Ultimate divisions without a midvein. Amesium, Newman. 



ASPLENIUM RUTA-MURARIA. Wall-Rue. White Maiden-hair. 

 TAB. XXXII. 



Fronds deltoid, bipinnate : pinnules rhomboid-wedge-shaped, 

 notched or 1 toothed on the upper margin. Indusium jagged. 



Asplenium Ruta-muraria, Linnaus. Smith. E.B. 150. Hooker 

 and Arnott. Moore. Babington. Amesium Ruta-muraria, 

 Newman, Hist. Brit. Ferns, 253. 



Very common on old walls throughout the kingdom, but indi- 

 genous to the mountainous and subalpine portion of it, where it 

 grows in the fissures of the rocks : its original migration from the 

 latter is indicated by the fact of its occurrence being gradually less 

 frequent as we advance from the central counties of England toward 

 the eastern coast. Its predilection for brick walls was noticed at 

 an early period, hence the common English name, and it may be 

 accounted for by the preference it exhibits in the wild state for 

 rocks of calcareous composition. In general appearance and sta- 

 ture it is very much diversified ; in the low countries, as a wall- 

 plant, we are familiar with it as one of small size, with fronds 

 sparingly divided, from half an inch to two inches in length; 

 while, in the rocky clefts of the hills of Derbyshire, Wales, and 

 Scotland, they attain a length of six or eight inches, and a branched 

 habit that might readily induce the casual observer to regard it as 

 a different species. Our figures are rather to be taken as expressive 

 of the ordinary than of the alpine form, which latter is subject 

 to considerable deviation. The fronds grow in tufts from the ex- 

 tremity of a slowly extending and branching rhizoma ; they are of 

 a thick, almost leathery substance and deep green colour, but in 

 exposed situations always covered with a glaucous secretion, whence 

 the name White Maiden-hair. In young and starved specimens, 

 the fronds are sometimes undivided or only simply pinnate with 

 roundish or reniform pinna?, but the more compound character and 

 triangular outline above assigned prevail even in comparatively 

 small plants. The normal arrangement of both pinna? and pin- 

 nules is alternate, but they are not unfrequently opposite in the 

 dwarfer forms, and the latter vary in figure from bluntly wedge- 

 shaped to rhomboidal, more or less attenuated in both directions, 

 so as to become in some instances almost linear ; under all circum- 

 stances the upper margin is irregularly toothed or serrated, the 

 wedge-shaped base entire. The veins diverge in a flabelliform man- 



