154 VI. POLYPODIACEAE. § 10. POLTPODIEAE. 



a.a. Sori lineai" or lineai'-oblong, more than 3 X as long as broad, continuous 

 or interrupted. 



$. Sori more or less oblique to the costa and mai'gin, many on eacl 

 side of the costa. No. 71. Poly|tocliniu, § Selliguea 



§ 11. ACROSTICHEAE. 



*. Fronds dimorphous, the fertile ones dichotomously branched, the bai-rec 

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



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

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



3. 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. Elaphoglossuin 

 3.3. Fronds divided, the fertile ones conti'acted. 



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



like, with the veins united at the base by costal lines oi 



spurious veins. No. 79. Slenochlaena 



J.J. Rhizome erect or creeping, neither nigh-soandent nor cable 



like. Fertile fronds not Lomaria-like, without costal line! 



or spurious veins. No. 80. Polybotrya 



S.2. Veins forming 1 — 2 rows of areolae against the costae and costula( 



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



2.2.S. Veins anastomosing more copiously, and generally irregularly. 



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



simple fronds. No. 81. Hymenolepis 



ti.u. Fertile region restricted to the higher segments of pinnatifid o 



pimiate fronds. 



h. Pinnae free, not articulate to the rachis, ± uniform o 

 the fertile ones rarely linear. No. 83. Acrostichum 



