VI. POLYPODIACEAE. § 4. PTERIDEAE. 1 



CO. Fronds mostly divided; leaflets not articulate 

 the rachis. 

 d. Veins free. 



e. Spores bilateral, + bean-shaped ; indusii 

 mostly double. No. 46. Paeisi 



e.e. Spores globose to tetrahedral; indusii 

 always single. 



f. Fronds finely dissected. Sori a 

 indusia ± meeting against t 



d.d. 



a.a. Stipes with 3 or more, free vascular strands. 



.'. Stipes with 2 stout and 1 to several finer strar 



placed altogether in a circle. Fronds dimorphous, 



utmost 2-pinnatifid. No. 48. l^omari 



.'..'. Stipes with many (12 — 24) irregularly placed strani 



Fronds uniform, at least 2-pinnate at the base. 



No. 47. Pieridiui 



% 5. BLECHNEAE. 



tri superficial. 



Sori long, linear, 1 on each side of and + close to the midri 



of the ultimate segments, continuous or interrupted. 



3. Fronds dimorphous; fertile pinnae much contracted and t 

 sori filling up nearly the whole space between the marg 

 and the costa. Indusium submarginal. (No. 48. Liomarii 



3.3. Fronds not dimorphous; fertile pinnae not contracted; s( 

 distant from the margin like the indusia. 



UCES. 9 



