1S2 HISTORY OF BRITISH FERNS. 



drium septentrionale ; to wliicli Amesium 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. Ruta-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, 



