165 



KEY TO GENERA. 



Vernation circinate in all genera except Ophioglossum. 

 Fructification dorsal. 

 Fructification spicate. 

 Fructification paniculate. 



I 



II 

 III 



I. FRUCTIFICATION DORSAL. 



Sori covered with an indusium. 

 •8ori naked. 



INVOLUCRATE.E. 

 Indusium cup-shaped. 

 Indusium tubular or hood-like. 

 Indusium continuous, marginal. 

 Indusium semilunate. 

 Indusium kidney shaped. 

 Indusium linear-oblong, sometimes curved. 

 Indusium orbicular, attached by the centre. 

 Indusium elliptical, apparently doubled. 

 Indusium bearing the capsules attached to its 



under surface. 

 Fertile fronds contracted, pinnate. 



1 Fronds herl)aceous, plant small. 



1 Stem arborescent, pinnje similar. 



1 Stem arborescent, having baiTen multifid 

 pinnae at base of frond. 

 2 Indusium 2-valved. 

 '2 Indusium entire or nearly so. 

 2 Indusium attached by base and sides. 

 2 Indusium attached by base only. 



3 Indusium opening outwards 



3 Ind usium at first globose, not quite continuous. 



.3 Receptacle punctiform. Fronds coriaceous, 

 except P. geraniifolia. 



3 Receptacle continuous. Fronds herbaceous, 

 except P. aquilina. 

 I Veins netted. 

 4 Veins free. 



o Pinnae jointed to rachis. 



o Pinnse not jointed to rachis. 



5 Frond simple. 

 6 Sori marginal. 

 6 Sori intramarginal. 



EX-INVOLUCRATE^. 



Scjri rotund, distinct, capsules numerous. 

 Sori rotund, confluent, marginal. 

 Sori linear or oblong, sometimes forked. 

 Sori linear, continuous. sub-intramarginaK 



Involucratej:. 

 Ex-Involucr ate^ . 



ASPLKNICM. 



AsPIDIUM. 



DlDYMOCHL^NA. 



Adiautdm. 



WOODSIA. 



Cyathka. 



Hemitelia. 

 Hymenophyllum. 

 Trichoma NEs. 

 Davaelia. 

 Cystoptrris. 



LiNDSAYA. 

 CHEILAXrHES. 



Pell^a. 



Pteris. 



lonchitis. 



Hypolicpis. 



Nephrolepis. 



Xephrodium. 



Oleandra, 



LOMARIA. 



Blechnum. 



POLYPODIUM. 

 XOTHOCHLiENA . 



Gimnogramme. 



VlTTARU. 



