1'TKU11H:.K — I'TKlilS. 99 



on tlie lower side; soriis on a siil)inarj;iiiiil strantl ronnrctiiij,' tlic cmls of tlie 

 veins, wantiiifi in tlie sinus between tlie sef^nients, proteeteil by the reflexed 

 ami specialized niar<,Mn, without an extroise indusiuni. A genus of 

 terrestrial fer!i>. Mii>>t rcmaikuMe for the poor (lelinilion of the species. 

 Ainoii;,' our species, /'. rrilicii and /'. iiu<i(lri<iur\t(i are especially notable for 

 the number ii their more or less distinct forms and related species. 



1. Veins free. 



2. Fronds simply pinnate. 



3. Pinna; ( uneate at base (\) P. opaca 



3. Plnnje truncate or cordate (2) P. louiiifolia 



2. Lowest pliuia" forked or pinnate. 



3. Pinnules or sPKnienta of lowest plnnse 1 to 3. 

 4. Fronds all equally pliiiiiUe. 

 5. Sterile fronds serrate. 



6. Stipes pale (3) P. crctica 



6. Stipes dark (4) P. melanocaulon 



5. Sterile fronds not serrate (5) P. pellucida 



4. Sterile fronds more pinnate than the 



fertile (6) P. cnsiformis 



3. Segments or pinnules of lowest pinn;p at 

 least 5. 



4. Only lower side plnnatifld (7) P. semipiitnata 



4. Both sides Incised. 



5. Only plnnatifld. 



6. Apex serrate (8) P. distans 



6. Apex entire (9) P. licteromorpha 



5. Pinnate P. (Uspar 



2. Lower pinnae at least biplnnatifld. 



3. Lowest pinnfp not greatly enlarged. 

 4. Frond not over 1 m high. 



5. Fronds all alike (10) P. quculriaurita 



5. Fronds dimorphous (11) P. grevillcaiia 



4. Frond well over 1 m. high (12) P. cxcelsa 



3. Lowest pinnae greatly enlarged (13) P. Jongipes 



1. Veins forming areolte along costa, otherwise free. 



2. Ultimate segments abruptly widened at base (14) P. patois 



2. Ultimate segments not abruptly widened. 

 3. Lowest pinnae of moderate size. 



4. Margin entire (15) P. biaurita 



4. Sterile margin crenate, large fern (16) P. kleiniaiia 



3. Lowest pinna; greatly enlarged (17) P. tcalUchiaiia 



1. Veins more copiously anastomosing (18) P. triparlita 



(1) P. opaca .T. Sm. Stipe stronf.', erect, pale, finely pubescent: frond 

 60 to !>(» cm. hi-rh, oblong, simply pinnate; pinme in numerous ojjposite pairs, 

 the largest 30 cm. long, narrowly linear, entire, cuncate at base, coriaceous, 

 glabrous except for the costa beneath; racliia pubescent like the stipe; veins 

 sunk in the froml and only visible as faint striations: indusiiun narrow, 

 brownish. 



Sainar or (^ebu, Cuming 342. 

 Celebes. 



(2) P. longifolia L. Stipes clustered. l.> to 30 cm. high, firm, erect, 

 pale, more or less clothed at the base with pale In-own scales; frond 30 to 

 50 cm. high, 10 to 20 cm. broad, attenuate below, simply pinnate; pinntie 

 sessile, numerous. 10 to l.'> cm. long, the lowest reduced, the upper linear, 



