PARKEXIACEAE 59 



the fronds firm, oblong or ovate-oblong, 40 to 90 cm long, the lobes 8 to 

 20, ascending, cut nearly to the midrib, 2 to 4 cm wide. Sori in regular 

 rows, one row on each side of each main vein running to the margin. 



Occasional on trees, old wajls, etc., sometimes cultivtited; throughout the 

 Philippines. Southern Asia to Australia and Polynesia. 



2. D. descensa Copel. 



Rootstocks stout, fleshy, densely covered with brown scales with long 

 caudate tips. Humus-gathering fronds ovate to oblong-ovate; coriaceous, 

 concave, imbricate, brown and shining, 5 to 6 cm long^j base deeply cordate, 

 subentire, or lobed above. Stipes of the ordinary fronds 5 to 25 cm long, 

 narrowly or broadly winged, the fronds oblong, 25 to 40 cm long, cut nearly 

 to the rachis into very distant, altei*nate, oblong-lanceolate, ascending or 

 spreading lobes 8 to 13 cm long, the lobes 7 to 12 on each side, much 

 narrower than the sinuses, the lower lobes much reduced. Sori in regular 

 rows or somewhat scattered. 



On dry ledges and on trunks of small trees in ravines opposite Gua- 

 dalupe; of local occurrence in Luzon. Endemic. 



16. ACROSTICHUM Linnaeus 



Very coarse tufted ferns from thick suberect rootstocks, -the stipes not 

 jointed to the rootstock. Frond large, simply pinnate, the pinnae with 

 a prominent midrib, the veinlets distinct, freely anastomosing, the upper 

 pinnae ip part or whole fertile. Sporangia densely covering the backs of 

 the fertile pinnae, except the midrib; indusium none. (Greek "tip" and 

 "row," allusion to the upper pinnae bearing the sori.) 



Species 3 or 4 in the tropics of both hemispheres, 1 in the Philippines. 



1. A. aureum L. Lagolo (Tag.). 



Rootstock stout, woody, scaly. Stipes clustered, stout, glabrous, 30 to 

 50 cm long. Fronds 50 to 200 cm long, the pinnae oblong, coriaceous, 20 

 to 50 cm long, 4 to 6 cm wide> base stipitate, apex obtuse or retuse, some- 

 times mucronate. Fertile upper pinnae somewhat smaller than the lower 

 sterile ones, the lower surface densely covered with the brown sporangia. 



Common in open brackish swamps; throughout the Philippines near the 

 sea, occasional in suitable habitats inland. Tropics generally. 



2. PARKERIACEAE (Water Fern Family) 



Aquatic or subaquatic succulent plants growing in shallow water or in 

 mud, the rootstock short, erect. Fronds pinnately divided, somewhat di- 

 morphous, the veins anastomosing, but more copiously in the sterile than 

 in the fertile fronds. Sporangia dorsal, not gathered into sori, scattered 

 irregularly on the few longitudinal veins of the fertile fronds, parallel to 

 the margins and midrib, the indusium none, but the margins of the fronds 

 broadly recurved, hardly changed in texture, the edges meeting with the 

 midribs and quite enclosing the sporangia lyhen young. Annulus vertical, 

 broad, incomplete, short, or interrupted by the very short stalk of the 



sporangium. 



A single genus and species, in all tropical countries. 



