132 
HISTORY OF BRITISH FERNS. 
drium septentrionale; to which Amesiwn septentrionale 
has to be added as another synonym. 
In cultivation it requires sandy peat-soil mixed with 
rubbly porous matter; and in uncongenial situations the 
shelter of a close frame or bell-glass. 
Asplenium germanicum, Weiss. 
The Alternate Spleenwort. (Plate XIII. fig. 3.) 
One of the rarest of our native Ferns, and perfectly 
distinct from A. Buta-muraria, of which some botanists 
have thought it to be a variety. 
The plant grows in little tufts, the fronds being from 
three to six inches high, sub-evergreen, narrow-linear in 
form, pinnate, divided into distant, alternate, wedge- 
shaped pinnae, one or two of the lowest having generally a 
pair of very deeply-divided lobes, the upper ones more and 
more slightly lobed, all having their upper ends toothed or 
notched. The whole frond is quite small, and the parts 
narrow, which, added to their opacity, renders the vena¬ 
tion indistinct; there is no midvein, but each pinna or 
lobe has a vein entering from the base, which becomes two 
or three times branched as it reaches the broader parts 
upwards, six or eight veins generally lying near together, 
