THE RUE-LEAVED SPLEEUWORT, 
or Wall Rue. 
Asplenium Ruta-muraria. — Linnaeus. 
This is a very diminutive Eern, growing, as its 
name implies, upon old walls, and very common on 
the limestone rocks, like the Rne in general appear- 
ance ; sometimes not above an inch high, seldom in 
the most favoured situations reaching to the height of 
six inches. Its fronds are numerous, of bloom- 
covered (glaucous) green, usually triangular in outline, 
bipinnate, and with a stipes about half the entire 
length of the plant. The pinnae are alternate, with 
rhomboidal, or roundish-ovate, or obovate pinnules, 
the base wedge-shaped, tapering into a more or less 
distinct petiole, the apex rounded or truncate, or 
sometimes acutely prolonged, always toothed with 
small or nearly equal teeth. The more luxuriant 
fronds become almost tri-pinnate, the pinnules deeply 
pinnatifid, and the lobes formed like the ordinary 
pinnules. When the plants are quite young, the 
fronds are simple and roundish kidney-shaped. At a 
later stage they are occasionally only once pinnate, 
with pinnatifid pinnae. The upper margins of the 
