CHARACTERS OF TRIBES AND GENERA. 325 



neria, and Camptosorus. The first section contains four 

 species, which have free venation ; in the other three 

 sections the veins anastomose, and are noticed further on. 



Sp. S. vulgare, Sm. (v v.) ; S. Hemionitis, Sw. (v v.). 



S. Hemionitis is found only in the south of Europe, 

 while S. vulgare is widely spread throughout the temperate 

 regions of the Northern Hemisphere ; it abounds in Europe, 

 and in this country is well known as the Hart's- tongue 

 Fern, and of which there are numerous abnormal forms, 

 no less than 160 being recorded in Mr. Stansfield's Cata- 

 logue. For S. Krebsii, Kze. in Sclik. Supp., t. 74, see 

 Lomaria. 



185. DIPLAZIUM, Sw. (1800). 

 Asplenium sect. Eudiplazium, Hook. Sp. Fil. 



Vernation fasciculate, erect or decumbent, acaulose or 

 sub- arborescent. Fronds simple, pinnate, or bi-tripinnate, 

 1 to 5 feet high, smooth, rarely pubescent. Veins forked 

 or pinnate ; venules free, the whole or the lower venules 

 only sporangiferous on both sides, forming binate linear 

 sori, each furnished with a linear indusium, the one opening 

 interiorly, the other exteriorly. 



Type. Asplenium plantagineum, Linn. 



Illust. Hook, and Bauer, Gen. Fil., t. 55 B. ; Moore, 

 Ind. Fil., p. 41 B. ; J. Sm., Ferns, Brit, and For., fig. 

 Ill ; Hook. Syn. Fil., t. 4, fig. 38 d. f. 



OBS. This genus differs only from Asplenium in the 

 sporangia being produced on both sides of the venules, 

 each furnished with its own indusium, thus forming binate 

 sori : this character is constant to most of the species, 

 especially those with simple or pinnate fronds, but in those 

 with more compound fronds, the binate sori are only found 

 on the lower exterior venule of one or more of the fascicles, 



