217 



PAGE 



TRIBE XII. ACROSTICHE^; 



Sori spreading over the whole under- 

 surface or rarely over both surfaces of the 

 frond, not confined to the veins only. 

 Fertile fronds or segments always more or 

 less contracted. 



Fronds of two forms : the fertile 

 fronds contracted and very narrow ; the 

 barren fronds simply pinnate ; the pinnae 

 leathery in texture ; veins simple or forked, 

 fine and close, generally quite free to the 

 margin, rarely anastomosing ; stipes 

 adherent to the rhizome ; pinnae articu- 

 late with the rachis. 



Genus XLIV. Stenochlaena J. Sm. 181 



Fronds pinnate, bipinnatifid or almost 

 pinnate, bipinnate ; sterile frond generally 

 proliferous ; fertile frond much contracted ; 

 veins pinnate, all free ; stipes adherent to 

 rhizome. Genus XLV. Polybotrya H. B. K 182 



Veins copiously anastomosing with free 

 veinlets in the meshes ; main veins distinct 

 or not distinguished from the rest ; fronds 

 simple or pinnate, generally of two forms, 

 the fertile being much contracted, or ' 

 rarely simple and all similar, bearing the 



