JULY. 



211 



FERN CLASSIFICATION.— No. VI. 



The tribe Cyatheinece includes three lesser sectional groups, which 

 are distinguished in the manner following : first, by characters derived 

 from the covering, or absence of covering, to the sorus, and next by the 

 £_""rr.ngement of the fructification. The receptacles, it will be remem- 

 bered, are always elevated, in the plants referred to this tribe. 

 Sori involucrate, i. e. with inferior cup-like indusia — 



Fructifications thyrsiform . . . . . §1. Thyrsopteridece. 



Fructifications dorsal . . . . . . |2. Cyathece. 



Sori naked, i. e. without indusia . . . . • |3. Alsophilece. 



The T/iyrsopferidece are a very small group, consisting of a single 

 genus and species, as far as 

 yet known. This genus is 

 Thyrsopteris. It is a large- 

 growing Fern, with a short 

 thick decumbent rhizome, 

 and very ample much divided 

 fronds, of which a portion, the 

 basal pinnules of the lower 

 pinna?, are fertile, while the 

 rest is sterile. In the sterile 

 parts the ultimate divisions^ 

 are small, while the fertile 

 parts consist solely of thyr- 

 siform collections of stalked 

 cup-shaped involucres, con- 

 taining the spore-cases, no &• Thyrsofterideje : Thyrsopteria elegans. 



leafy portion being produced. As in the other Cyatheineous plants, 

 the spore-cases are more or less oblique laterally compressed. 



The Cyathece are more normal-like than the foregoing, the fronds 

 being all in the usual leafy condition, and bearing the sori on their 



under surface. These sori are 

 in cup-like involucres, more 

 or less perfectly formed. The 

 involucres are much like some 

 of those of the JPeranemece, 

 but the distinguishing feature 

 of the Cyathece is, that in 

 addition, the receptacles are 

 elevated. There are but three 

 genera referred to the present 

 section : — Cyathea, in which 

 the involucre forms a complete 

 cup ; and Hemilelia and Am- 

 phicosmia, in which the invo- 

 lucres are half cup-shaped, the 

 anterior side of the cup being 

 deficient. The two latter are 

 distinguished by their venation, 



\i, LVATne^s : Hemitelia speciosa. 



