514 Key to the System of 



POX.YPO3DXUBX. 



2147. Fronds mainly beset with appressed roundish cilio- 

 lated scalelets. 



Chiefly on trunks of fern-trees, dwarf ; root-stock much 

 creeping ; rootlets copious ; fronds scattered, stalked, of 

 very thick texture, entire ; sterile fronds often quite 

 short, from orbicular- or rhomboid -obovate to elliptical- 

 spatular ; fertile fronds somewhat elongated, from 

 narrow-elliptical to broad-linear ; vestiture appressed, 

 shining, greyish or brownish, occupying closely the under- 

 side of the fronds ; venules concealed ; fruit-masses large, 

 occasionally oval, rather crowded or even merging into 

 each other. P. serpens. 



Fronds glabrous or mainly beset with short spreading 

 hairlets 2148 



2148. Fronds all entire. 



Chiefly on trunks of fern-trees, dwarf, sometimes quite 

 minute ; fronds tufted, short-stalked, firm, exceptionally 

 somewhat bisected, from narrowly lanceolar-elliptical to 

 broad-linear, gradually attenuated towards the base ; 

 venules all diverging ; fruit -masses large, from oval- to 

 linear-elliptical, biseriate. P. Australe. 



Fronds all or mostly divided 2149 



2149. Fronds quite small. 



Chiefly on the trunks of fern-trees, tufted; fronds firm, 

 mostly simply pinnatisected, seldom any undivided, 

 much decurrent at their stalk-like base, the segments 

 from narrow-semilanceolar to broad-linear, almost serrate ; 

 longest towards the middle of the frond ; venules 

 all diverging ; fruit masses from oval to orbicular. 



P. grammitidis. 



Fronds comparatively or quite large ... ... 2150 



2150. Fronds of firm texture. 



Chiefly on stems and branches of trees and also on trunks of 

 arborescent ferns ; root-stock widely creeping, with 

 numerous rootlets ; fronds pinnatifid or some undivided, 

 slightly flexuous, very shining, their lobes often seini- 

 lanceolar and generally few only, sometimes long, rarely 

 again divided ; venulation rather prominent, reticular ; 

 fruit-masses orbicular, comparatively large, distant, 

 biseriate, their receptacles protruding on the surface of 

 the frond. Figure 151. P. pustulatum. 



