OUR NATIVE FERNS. 



GENUS vr. 



ATHYRIUM. RoTu. 



The present genus of Roth, holding a midway position 

 between Asjrulitim and Asplenium, is rejected as a genus by 

 some of our greatest authorities, being united to Asplenium. 

 Sir W. Hooker places it in Asplenium as a sub-genus, dividing 

 Asplenitan into the groups Tham?wpteris, jEuasplem'uni, Athy- 

 rium, Eudiplaziimi, Anisogonium, and KcmidicUjwn. Seven 

 species are placed under Thamnopteris, and commonly called 

 Bird-nest Ferns, none of which are found in Europe. They 

 are distinguished by a marginal longitudinal vein, with which 

 the apices of the transverse veins unite, and there only. Fronds 

 simple; sori like Euasplenium. Two hundred and seven species 

 belong to Euasplenium, and are distinguished by the sori being 

 plane or nearly so, nearly always single; veins free, simple, or 

 branched, and the fronds undivided, lobed, or ]>almated, pinnate 

 or bipinnate. In this large branch are to be found Asplenium 

 Hemionitis of Southern Europe, A. attenuatum of New Holland, 

 A. marinum of Great Britain, A. lucichim of New Zealand, A. 

 angtistifoKum of the United States, A. compressum of St. Helena, 

 A. trichomanes of Great Britain, A. Petrarchce of Southern 

 France, A. cbeneum of North America, A. monanthemum of 

 Madeira, A. viride of England, A. septentrionale of Great 

 Britain, A. Germanicum of Great Britain, A. ruta-muraria of 

 Great Britain, A. Jissum of Southern Europe;, A. adiantum- 

 iiigrum of England, A. lanceolatum of England, and A. fontanum 

 of England. 



VOL. II. B 



