94 



CHARACTERS OF TRIBES AyS GENEKA. 



areoles ; the costal areoles al-rrays vacant. Eeccptaclcs 

 punctiform on the combined apices of the excarrent vein- 

 lets. Sori round, transversely one to two serial, naked. 



Type. Polypodlum aureum, Linn. 



Ilhist.— Hook, and Bauer, t., 112. Moore Ind. Fil., p. 58, 

 figs. 1—3. J. Sm. Ferns. Brit, and For, fig. 9. Hook. 

 Syn. Fil., t. 5, fig. 48, g. 



Obs. — This is a vyell-marked genus, containing about 

 half a dozen species, all natives, of the West Indies and 

 Tropical America. In general habit it resembles Gonio- 

 pMehiuin, but is distinguished by the sori being borne on 

 the combuied apices of at least two excurrent veinlets, and 

 by the costal aeroles having no free veinlet. 



Ex. — P. aureum (itn«.),(v v.),P. sporodocarpum(Ty'i7W.), 

 (v v.), P. areolatum {Willd.), (vv.), P. pulvinatum (Lmk), 

 (v v.), P. decumanum (IFiZW.), P. diotyocallis (jfee), (v v.). 



Sect. 3. — Pleueide.e. 



12.— Pleuridium, Pnsl (1836). 



Fohjpodium, Sp. auth,, Hooh. Sp. Fil. ; Phymatodes, section 



Pleuridium, Presl in pari. 



Siircidum short, or elongating. Fronds simple, rigid, 

 papyraceous, or coriaceous, from G inclies to 2 feet in 

 length, thick marginate. Primary rciiis costasform, elevated, 

 straight. Veimles compound anastomosing. lieceptacles 

 compital, punctiform. Sori round or oblong, obliquely one 

 or two serial between the primary veins. 



Type. Pohjpodium crassifolium, Linn. 



Illust. — Schott. Gen. Fil. t. 1 (Anexetum). Hook, and 

 Bauer, Gen. Fil., t. 29. J. Sm. Ferns, Brit, and For., 

 fig. 22. 



Obs. — Presl arranges the species of Phymatodes under 



