A8PLENIUM RUTA-MURARIA. 51 
form, and extending to the notches or teeth. The fruc- 
tification is in lines on the inner side of the veins, and 
when ripe is dark brown, but at first covered with a 
white membrane (indusium), which is soon lost as the 
fructification spreads, runs together, and finally covers 
the whole underside of the leafit. The indusium bursts 
with a jagged edge on the inside; but, as Mr. Charles 
Johnson observes, this is of small importance in specific 
distinction unless far more decided than in this instance. 
This Fern sends up its new fronds in May and June, 
and they retain their verdure all the winter. The fruc- 
tification is ripe in August. 
It is found in moist, shady clefts of limestone rocks 
and in the crevices of old walls, abundantly in the 
midland and southern counties, but more rarely in those 
of the north and east of England. It is a native, also, 
of most parts of Europe, and from New York to Carolina, 
in America. 
It was known to our earliest herbalists as a native of 
this country. Thus, Gerarde says, " Stone Rue groweth 
upon old walls near unto waters, wells, and fountains. 
I found it upon the wall of Dartford Church, in Kent, 
hard by the river side, where the people ride through ; 
and also upon the walls of the churchyard of Sitting- 
bourne, in the same county, in the middle of the town, 
hard by a great lake of water ; and also upon the 
church walls of Rayleigh, in Essex; and in divers other 
places." Matthiolus was the first to call it Ruta muraria, 
or rather Ruta muralit, and Gerarde names it after him, 
" Wall Rue, or Rue Maiden-hair," as well as Stone Rue 
