﻿134 VI. POLYPODIACEAE. § 10. POLYPODIEAE. 



a.a. Sori linear or linear-oblong, more than 3 X as long as broad, continuous 

 or interrupted. 



;ic. Sori more or less oblique to the costa and the margin, many on 

 each side of the costa. No. 71. Polypopiuni, § Selliguea. 



■X-.^. Sori parallel to the costa or the margin, 1 on each side. 

 S. Fertile fronds simple as are the barren ones. 



No. 75. DrymogloiSfSuiii. 

 $.$. Fertile fronds 3-partile, barren ones sagittate. 



No. 76. Chrisloptcris. 



§ 11. ACROSTICHEAE. 



j[. Fronds dimorphous, the fertile ones dichotomously branched, the barren 

 ones adpressed to the substratum. No. 77. Platycerium. 



1.1. Fronds uniform or dimorphous, the fertile ones not dichotomous, whether 

 or not contracted, the barren ones not as in 1. 



S. Veins free, or sometimes the apices or bases of the veins united 

 by ± marginal or + costal lines. 

 3. Fronds simple, often more or less dimorphous. 



No. 78. Elaphoglosiiiiiii. 

 3.3. Fronds divided, the fertile ones contracted. 



4. Rhizome high-scandent, cable-like. Fertile fronds Lomaria- 

 like, vrith the veins united at the base by costal lines or 

 spurious veins. No. 79. Stenochlaena. 



1.1. Rhizome erect or creeping, neither high-scandent nor cable- 

 like. Fertile fronds not Lomaria-like, without costal lines 

 or spurious veins. No. 80. Polybotrya. 



2.2. Veins forming 1 — 2 rows of areolae against the coslae and costulae 

 (as in Pleocnemia), otherwise free. No. 81. Stenoseiuia. 



2.2.2. Veins anastomosing more copiously, and generally irregularly. 



a. Fertile region restricted to the linear or spoon-shaped apex of 

 simple fronds. No. 82. Hymenolepis. 



a.a. Fertile region restricted to the higher segments of pinnatifid or 

 pinnate fronds. 



*. Pinnae free, not articulate to the rachis, + uniform or 

 the fertile ones rarely linear. No. 83. Acrostichuni. 



