CXU. GENERA OP PEE5r3 : 



CitASFEDOPHYtLtTM, Fred; Pttchophyllum, Prist; Sph^hocionipMj 

 Fresl ; MECODiuti, Fresl ; Deematophlebium, P»*eai. 



Sori involucrate, i.e., seated within an extrorBe-ma^gina^ ob^ 

 long or sub-orbicular two-Talved involucre; the veins continued 

 into the receptacle, which is free included cylindrical or globose 

 at the apex, and bears sessile or sub-sessile lenticular or turbinate 

 spore cases. Veins dichotomously branched, simple and costa- 

 like in the ultimate segments, or simple parallel from a central 

 eoata in undiyided fronds ; vetmles free. 



Fronds simple or deeompoundly divided, pellucid membrana- 

 ceous. Ehizome creeping, usually filiform. — This group, which 

 is rather extensive, is in general well-distinguished from Trioho^ 

 manes by the involucres consisting of two separate valves, instead 

 of being blended into a oup. In some few species, however, where 

 the valves are combined below, this difference becomes merely 

 one of degree. 



§ Mymenoghimm, — Veins simple from a, central costa (fronds simple.) 

 Ex. : H. omentum, Cmi. 



§ Si/mettaph^llwm, — ^Veins simple costsrlike in tiie ultimate segments. 



Ex. : H. hirEutum, 8w. 

 H. ele^ans, Spr. 

 H. senoeum, Sw. 

 H. tunbridgense, Sm. 

 H. fuciforme, Sw, 

 H. crispatum, TFalL 



H. organense, Hook, 

 H. pmchellum, Sclilcch. 

 H. seruginosum, Cmrm. 

 H. unilaterale, Willd^ 

 H. dilatatum, Sw. 

 H. demissum, Sw, 



Orfier— POLTPODIACE.^. 2Vi4e— SCHIZ^IlfE^. 

 § 1 Lt&ode^. 

 (a) Yemsfree, 



158. LYGODIUM, Swao'tz, Schrad, Journ. 1800, ii. 7, 106, 



Ugesa, Cavunilles; HYSBoaLossuu, WiUdenow, in part; Gisoptebis, 

 Bemluvrdi; Odowtoptebis, Serjihardi; CTEisitrM, Michaux; Abthbo- 

 L7G0DE8, Pretl; Bamohdia, Mirlel; Vallifilix, Thmara ; Ophio- 

 GLOSSl sp., Awii^ 



Fructifications forming compressed distichous spikelets, ei- 

 serted on the marginal teeth. Spore-cases included beneath 

 ovate cucuUate imbricated persistent scariose braotiform imdnisia. 



