PTERIS. 49 



oentre and the margin. End of May. In- 

 deciduous, Easy of cultivation. Rarer 

 varieties exhibit the pinnae forked at top ; 

 or notched all round ; or deeply incised into 

 even or indented quasi-pimmlets. Of these, 

 the last, Cambricum (barren and much 

 later), is the most curious and worthy of 

 notice, its fronds being somewhat of an 

 oval form, and the pinna3 bulging out so 

 much in their centres as to leave an oblong 

 round of light all down near the stem. Its 

 native locality is North Wales. 



PTERIS. 



Sori on the back, forming a continuous line 

 along the margin. Indusium attached to 

 the slightly-recurved edge of the pinnulet. 



PTERIS AQUILINA. (Common Brake, or Female 

 Fern.} Fig. 18. Ordinarily from 2 to 3 

 feet, but rising occasionally as high as 7 or 

 8 feet. Root long and fibrous, creeping 

 horizontally; very succulent; and deeply 

 embedded below, throwing up its solitary 

 fronds at intervals, which soon cover large 

 patches of ground. A tall, erect, tree-like, 

 stem, velvety at its base, very brittle at 

 first, afterwards tough and wiry, with 

 simple, lateral, protuberances at top, 



4 



