2. POLYFODIACE^. 



13. 



14. 



tt Sori, at least one (usually the lowest) ou 

 each lobe paired, iiidusia opening ni oppo- 

 site directions . .. • „ /, ^, • ■'•^' 

 ii. Sori attached to a special vem parallel to the 



costa. (See also 20. Dnjmoglossum) . . 12 



iii Sori not confined to the veins but spreading on 



to the parenchyma. Indusium • ^^ • ^^ 

 b Sori on the fertile vein or terminal and then 

 sometimes on a special marginal vein. 

 Indusium proper rarely present but otten 

 formed by the margin of the frond (Pteri- 

 dece) : — 

 i Sori occupying the whole fertile vein except- 

 ing the ends {Gymnogramminece). Fronds 

 hairy : — 

 Fronds 1-2-pinnate. Veins free . 

 Fronds usually simple 3-lobed. Veins copiously 

 reticulate and completely sonferous . . 



ii. Sori occupying the ends of the veins only and 

 sometimes confluent. Stipes pohshed 



black : — • , . -j * ^.v. 



t Sdri not confluent on the inside of the 

 recurved margins of the frond (Cheilan- 

 thinece) : — . 



Veins thickened at the end, free . ^ • 1» 



Veins not thickened at the ends, anasto- 

 mosing . . • „ :, • \ 

 ft Sori confluent on the inside of the recurved 

 margin of the lobes of the frond . . 17 

 iii. Sori on an jntramarginal vein connecting the 

 ends of the normal veins. Veins other- 

 wise free : — „ , „ ^ ■,. , 

 Small palm-like fern with flabellate dicho- 



tomously divided fronds . . . . 18 



Fronds pinnately divided. Xo extrorse indu- 

 sium . . . • , • • ■ 1 

 As in Pteris but with a second extrorse indu- 

 sium . . • • ^ . • -, • j' 

 B Indusium never present and margin of frond unmodi- 

 fied Frond articulate on the rhizome. \ enation 

 never herring-boned. Sori dorsal on the frond, 

 round or ellipsoid (linear or in lines in Dnjmoglossum) 

 (Polypodiese) : — ., . , ^ ,. a 

 1 Fronds simple undivided, fertile fronds contracted. 



re'tiiJdate'""'""''"! '"'' ?"'''''.'' '' '''''". "''• 20. Drymoglossum. 

 2, Fertile fronds not contracted. Sori scattered :— 



a. Fronds not dimorphic :— , . 

 Fronds glabrous or with simple hairs, veins free . 

 \s in Poii/i;odu«/i but veins reticulate • ., ,• "^' 

 Fronds densely covered beneath with stellate ^^ 



hairs . . . • •., • • • "^• 



b. Fionds dimorphic. Barren sessile . _. • -<5. 

 II. Sori without indusium. densely covering both veins and 



parenchyma of the whole or part of the undersurtace of 

 fronds (Acrostichece) : — 



Diplaziurn. 

 Blechnum. 

 Stenochlcena. 



Gymnogrammei 

 Hemionitis. 



Cheilanthes. 

 Doryopteris. 

 Adiantum. 



Actiniopteris. 



Pteris. 



Pteridium 



(p. 1204). 



Polypodium. 

 Pleopeltis. 



Niphobolus. 

 Drynaria. 



\. Fronds simple dimorphic. Fertile much contracted •.— 

 Veins much anastomosing with free included veinlets 



but often indistinct. Stipes not articulate . 



Veins much as in Gymno pteris. Sori at first hnear and 



parallel to costa, ultimately confluent. Stipes 



articulate on the wide creeping caud ex . ,• ^ • 



B Fronds simple 3-lobed or pinnate, fertile not contracted. 



Sori at first confined to the copiously reticulate veins 



C. Fronds pinnate, very large :— 



Veins simple and forked free, very close, Pmnse 

 articulate, fertile pinnae contracted 



1185 



24. Gymnopteris. 



Drymoglossum, 

 Eemionitis. 



25. Stenochlcena. 



