LYCOPODIACE.-E. 203 



GENERA OP FILICES 



A. Sori dorsal or within the dorsal margin. 

 Tribe 1. POLYPODIES. Sori without an indusium, circular 

 or nearly so. 



1. POLYPODIUM. Sori large circular, golden yellow. 



2. CRYPTOGRAMME. Sori. marginal, at length uniting, and covered 



by the reflexed margin of the frond. Barren and fertile 

 fronds distinct. 



Tribe 2. ASPIDIE^E. Sori nearly circular, covered by an 

 indusium. 



3. ASPIDIUM. Sori circular or reniform, covered by an indusium. 



4. CYSTOPTERIS. Indusium springing from beneath the sori. 

 Tribe 3. ASPLENIE JS. Sori linear or oblong, covered by an 



indusium. 



5. ASPLENIUM. Indusium opening on one side. 



6. SCOLOPENDRIUM. Indusium opening by a slit along the centre. 



7. CETERACH. Indusium erect, concealed by scales. 



Tribe 4. PTERIDE^E. Sori covered by a marginal indusium 

 or cuticle of the frond. 



8. PTERIS. Sori linear, continuous on the margin of the frond. 



9. BLECHNUM. Sori distant from the margin. Barren and fertile 



fronds distinct. 



B. Sori in marginal involucres. 



Tribe 5. HYMEN OPHYLLE^E. Sori in a marginal cup or 

 involucre. 



10. TRICHOMANES. Sori within a cup-shaped involucre. 

 11. HYMENOPHYLLUM. Sori within a 2- valved involucre. 



OED. 90. OSMUNDACEJE. 



Capsules arranged in clusters at the extremity of the frond; 

 ring obscure. Fronds circinate when young. 

 1. OSMUNDA. Capsules in branching spikes. 



ORD. 91. OPHIOGLOSSACE.E. 



Capsules arranged on a separate branch of the frond ; ring obso- 

 lete. Fronds straight when young. 



1. OPHIOGLOSSUM. Capsules on a single spike. 



2. BOTRYCHIUM. Capsules on a branched spike. 



OED. 92. LYCOPODIACKE. 



Capsules sessile in the axils of terminal leaves, arranged as 

 spikes, or in a cavity at the base of the leaves; ring obsolete. 

 Fronds straight when young. 



