Vnt. OSMTJiNOA^OELA^E:. 



Stri dorsal (on the under surface of normal segments) or lateral (on the 

 margin of much contracted fertile segments). Sporangia with a very short, in- 

 complete, horizontal ring often consisting of a small group of thickened cells 

 only, opening by- a slit 'across the apex. 



Caudex thick, rarely arborescent. Stipes dilated at the base, not articu- 

 late to the caudex. Fronds large, at least simply pinnate, covered with a to- 

 mentum of long, woolly hairs when young, at length naked; veins free. 



Generally inhabiting temperate climates. 



Key to the genera. 



f. Fertile segments much contracted, articulate to the rachis. Sori globose, 

 placed in opposite, marginal clusters. Texture of the fronds herbaceous 

 or coriaceous. No. 88. Osmunda. 



•^.•^. Fertile segments not contracted, not articulate to the rachis. Sori + flat, 

 dorsal. Texture of the fronds membranaceous. No. 89. Ijeptopteris. 



88. 0SM:XJ]VDA., lAnMi. 



Sori subglobose, placed in opposite, marginal, thyrsoid clusters No in- 

 dusium. 



Fronds large, at least simply pinnate, herbaceous or coriaceous; leaflets 

 dimorphous, articulate to the rachis, the fertile ones much contracted; veins 

 free. Hk. Bk., Syn. Fil., tab. VIII, fig. 62; Diels, in Engl. & Prantl, Nat. 

 Pfl.Fam., I*, fig. 205. 



Pantropical, and extra-tropical in the northern hemisphere. 



Arrangement of the sections. 



$ 1. PLENASIUM. Pinnae at best lobed. 



§2. OSMUNDASTRUM. Pinnae deeply pinnatifid. (Not in Malaya). 



§ 3. EU-OSMUNDA. Pinnae pinnate. (Not in Malaya). 



