670 UNpDERWooD: FERNS OF THE PHILIPPINES 
bipinnate or tripinnate leaves eight to fifteen feet long, while 4xgr- 
opteris has four nominal species * nearly as large. 
Li ELELCALES 
The ferns proper with circinate vernation belonging to the lepto- 
sporangiate series are represented in the Philippines by several 
families distinguished as follows : 
I. Sporangia opening longitudinally, paniculate (or in Lygedium borne singly and 
covered by scales on narrow projections from the leaves). 2. 
Sporangia sessile, borne on a special marginal thread-like receptacle, surrounded by 
a cup-shaped or bivalved involucre ; texture translucent. 7. HYMENOPHYLLACEAE. 
Sporangia dorsal or marginal, attached directly to the lamina, usually collected in 
definite sori. 3- 
2. Sporangia nearly globose with a rudimentary ring. 1. OSMUNDACEAE. 
Sporangia pyriform with an apical ring. 3. SCHIZAEACEAE. 
3. Aquatic; leaves dimorphous ; sporangial ring broad or rudimentary. 
: 2. CERATOPTERIDACEAE. 
Terrestrial or epiphytic ; sporangial ring complete, vertical. 4. 
4. Sporangia sessile, wedge-shaped, radially arranged ; stems simple or (in all Philip- 
pine species) pseudo-dichotomous. 4. GLEICHENIACEAE, 
Sporangia sessile or short-stalked in rounded sori; usually arborescent. 
5. CYATHEACEAE. 
Sporangia usually long-stalked ; herbaceous, rarely with an arborescent caudex. 
6. PoLyPODIACEAE. 
To the above families belong the largest number of the ferns 
not only of the Philippines but of the entire world. While the 
greater part of the Philippine ferns bear a general resemblance to 
those of temperate regions there are many curious forms particularly 
among the epiphytic species that are quite unique and widely dif- 
ferent from our ordinary conception of a fern. The two families 
Gleicheniaceae and the tree-ferns (Cyatheaceae) are not represented 
in temperate America at all, and the filmies (Hymenophyllaceae), 
rare with us, are abundantly represented in the Philippines as in all 
tropical regions. 
FAMILY I. OSMUNDACEAE 
This family is represented in the Philippines by a single species 
of Osmunda, though it is quite possible that others may be found. 
* Synopsis Filicum reduces all the forms of Angiopteris to a single species, but 
Pres] defined ten, and DeVries and Harting who monographed the family in 1853 
recognized sixty! From the fleshy nature of the plants it is a genus that requires field 
study, and description or even identification from herbarium material is necessarily 
defective. 
