150 
HISTORY OF BRITISH FERNS. 
sharply two- to five-toothed segments. The venation con- 
sists of a midvein, which enters each lobe of the pinnule, 
and branches alternately into as many nearly parallel veins 
as there are marginal teeth, one venule being directed into 
each tooth. The narrow linear elongate sori are borne, 
rather close together, on these venules. This is a very 
rare plant. It has been found in a few Irish counties, 
and in Jersey ; and is also met with in the North of 
Europe, and more plentifully in the Canaries, Azores, 
and Madeira. It has usually been treated as a frame or 
greenhouse plant. The other names belonging to it are, 
Asplenium acutum^ Asplenium Virgiliiy and Asplenium 
productum. 
The ordinary forms of the plant ^re very commonly met 
with growing on rocks or old walls, and on hedge-banks in 
a sandy soil. The latter situations, where they grow most 
vigorously, are often beautifully adorned by their drooping 
tufts. The extreme forms are more rare. 
This is one of the more useful evergreen Ferns for shady 
rockwork, as it will grow with freedom if planted in sandy 
soil which is just kept moistened either by natural or 
artificial means. As a pot plant it is easily manageable. 
