CHARACTERS OF TRIBES AND GENERA. 205 



falcatum (iSw.) (v v.) ; C. caryotideum {Wall.) (v v.) ; C. 



Fortunei, /. 8m. (v v.) {Ferns, Brit, and For.) ; C. Jng- 



landifolium, Kunze (v v.) {Amhlia, Pr.) ; 0. nobile, Ewnze 



{Phaneroplilehia, Pr.) 



Obs. — The three first species are natives of India and 



Japan, the two latter of Mexico and Venezuela. 



Although I have not seen specimens of the Fern 

 described in the "Species Filicum" under the name of 

 Polypodmm {Gyrtotniphlebitim) duhwm, a native of Peru 

 and Ecuador, I nevertheless believe it to be a species of 

 Gyrtomimn ; and the reason for Sir William Hooker 

 placing it in Polijpodhim seems to mc to be consequent 

 on the sori having through age or otherwise lost the 

 indusinm. 



107. — Pleocnemia, Presl (1836). 

 'Ncphr odium ILooh. Sp. Fil. ; Polypodium, Gaud. 



Vernation fasciculate, erect, arboroid (vide Cuming). 

 Frauds bi-tripinnatifid, 12 to 16 feet long ; primary pinnte 

 li to 2y feet long; ultimate pinnce uniformly pinnatifid. 

 Veins of lacLnaa costseform ; venules forked, the lower ones 

 arcuately and angularly anastomosing, forming unequal 

 areoles next the costa ; the exterior ones free. Fertile 

 pinnules much narrower than the sterile. Sporangiferous 

 recepitacles medial on the free or anastomosiug venules. 

 Sori pnnctiform in a row on each side of the costfeform 

 veins of the lacince. Indtisium reniform. 



Type. Polypodium Leuzeanum, Gaud. 



lUust. Hook, and Bauer, t. ^1 ; Moore Ind. Pil., p. 70, A ; 

 J. Sm. Perns, Brit, and For., fig. 71. 



Obs. — This genus is founded on a single species, and 

 owes its generic importance more to its gigantic habit 

 than to any real structural difference by which to dis- 



