FOOT (F. J.) ON A VAEIETY OF ASPLENIUM RUTA-MUKABIA. 



59 



tufts of it grew on the very top of the wall, which is ahout eight feet 

 in height, and not in crevices in the vertical face, as is the usual habit 

 of this species. There was no difficulty in detaching the roots. Pro- 

 bably no British Pern is more variable than A. Ruta-muraria ; but I 

 believe the variation is generally due to peculiarity of situation, and is 

 lost under cultivation, the plant eventually resuming the normal form. 

 It is most likely to vary in rocky clefts in limestone districts, like Bur- 

 ren, or the hills of Derbyshire and Yorkshire. But there is nothing 



Asplenium Ruta-muraria, normal form. 



very remarkable in the habitat of the plant before us, except that the 

 wall is somewhat sheltered by trees. It seems to be unaccompanied by 

 plants of normal form, although these are plentiful enough on other 

 walls in the neighbourhood, some of which are much more densely 

 shaded. I have never seen a variety of A. Ruta-muraria like this, nor 

 am I aware that it is figured or described in any of the books on Perns. 

 The two figures annexed are accurately drawn by measurement, and 

 are the natural size. One represents a frond of the Pern before you ; 

 the other is from a cut, by Sowerby, of a good-sized frond of a normal 

 plant. The remarkable difference of outline between the two will at 

 once be apparent to you. 



