56 A FLORA OF MANILA 



Species 160 or more, in the tropics of both hemispheres, about 23 in 

 the Philippines. 



1. Veins free. 

 2. Fronds simply pin'nate, lower pinnae' shorter than the median ones. 



1. P. longifolia 

 2. Lowest pinnae pinnate, or pinnatifld; pinnules or segments few. 



2. P. ensiformis 



2. Lowest pinnae bipinnatifid 3. P. quadriaurita 



1. Veins anastomosing, forming narrow areolae along the costa only; upper 

 part of the frond simply pinnate, the lower pinnae forked and 



bipinnatifid 4. P. biaurita 



1. Veins copiously anastomosing; coarse ferns with 3-partite fronds. 



5. P. tripartita 



1. P. longifolia L. 



Rootstock short, the tips clothed with copious, brown, linear scales. 

 Stipes clustered, 3 to 15 cm long, more or less clothed at the base with 

 linear, spreading, brown scales. Fronds simply pinnate, oblong, 20 to 50 

 cm long, the lower pinnae shorter than the median ones; pinnae sessile, 

 numerous, 5 to 20 cm long, linear-lanceolate to linear, acuminate, entire, 

 base truncate, subcordate, or auricled, glabrous, subcoriaceous, the terminal 

 one often much longer than the others; veins close, usually once forked. 

 Sorus extending the entire length of the pinnae on both sides. 



Crevices of old dry walls, in thickets, on clifiTs, etc.; throughout the 

 Philippines. Most tropical and subtemperate countries. 



2. P. ensiformis Burm. 



Rhizome short, creeping, slender, paleaceous. Stipes slender, those of 

 the sterile fronds 5 to 10 cm long, of the fertile ones 10 to 30 cm long, 

 naked, erect, green. Fronds membranaceous, often mottled with gray, the 

 sterile ones 7 to 20 cm long, bipinnatifid or bipinnate, the segments oblong 

 to obovate, dentate, about 1 cm long. Fertile fronds 20 to 40 cm long, 

 simply pinnate, sometimes bipinnate, the segments few, linear, 5 to 15 cm 

 long, the terminal one usually much longer than the few, distant, simple 

 or pinnatifid lateral ones, acute or acuminate, often denticulate at the sterile 

 apex; veins usually forked, free. Sorus continuous. 



In shaded thickets, old gardens, etc.; widely distributed in the Philip- 

 pines. India to China southward to Australia and Polynesia. 



3. P. quadriaurita Retz. 



Roots clothed with soft brown hairs, the tips of the rootstocks paleaceous. 

 Stipes clustered, erect, 15 to 30 cm long, glabrous or nearly so, smooth, 

 green. Fronds oblong, 20 to 60 cm long, simply pinnate or the lower 

 pinnae again compound, the central terminal pinna elongated, acuminate, 

 cut nearly to the rachis into numerous, close, parallel, oblong to linear- 

 oblong, often falcate, obtuse, entire lobes 1 to 2 cm long; lateral pinnae 

 3 to 8 pairs or more, 8 to 20 cm long, 1.5 to 3 cm wide', deeply cut into 

 numerous lobes like the terminal pinna; veins usually once forked, free, 

 not forming areolae along the costa. Sori continuous along the entire 

 margin or interrupted in the sinuses and toward the ends of the lobes. 



Occasional in thickets, sometimes in gardens; widely distributed in the 

 Philippines. All warm countries. 



