48 



A TABLE OF THE GROUPS AND GENERA OF THE 

 BRITISH FERNS AND ALLIED PLANTS. 



I. VEB.^^ = FILICES. 



Floicerless plants, hearing seed-vessels {spore-cases) on 

 their leaves {fronds), at the bach {dorsal) or margins 

 {marginal). The British Ferns belong to groups ichich 

 are called Polypodiacete, Osmundace[e,«?«f?Opliioglos- 

 saccffi. 

 POLYPODIACE/E = Ferns having tlie leaves rolled up 

 in a circinate or crosier-likc manner uhile young ; and 

 the spore-cases girt with an elastic ring, and bursting 

 by an irregular transverse cleft. It comprises several 

 lesser groups or sections, called Fohipodiccv, Gijmno- 

 grammecc, Aspidiew, Aspleniew, Blcchnecc, Pteridew, 

 Adiantew, Woodsicce, and Ilymenophyllew. 

 § POLYPODIES = i'^<??';25 whose round clusters of 

 spore-cases have no special membranous cover {in- 

 dusium). It contains the genera Polypodium and 

 Allosorus. 



