PARKERIACEAE 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 em wide. Sori in regular 
rows, one row on each side of each main vein running to the margin. 
Occasional on trees, old walls, etc., sometimes cultivated; 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 em long, base deeply cordate, 
subentire, or lobed above. Stipes of the ordinary fronds 5 to 25 em long, 
narrowly or broadly winged, the fronds oblong, 25 to 40 cm long, cut nearly 
to the rachis into very distant, alternate, 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 in 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 em long. Fronds 50 to 200 em long, the pinnae oblong, coriaceous, 20 
to 50 em long, 4 to 6 em 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 subaquatie 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 when 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. 
