28 COPE LAN I). 



2. PHANEROSORUS Copeland. 



Fronds pendent with slender stipe and rachis, sympodially branched 

 as in Lygodium, each dwarf branch hearing a pair of one to three times 

 dichotomous pinnae; veins free or forming costal areola 1 ; sori usually 

 just outside these areolae; indusium hut slightly curved under the sporan- 

 gia; sporangia 10 to 14. Only one species known. 



Phanerosorus sarmentosus (Baker) Copel. Philip. Journ. Sci. Pot. 3 (1908) 

 344. (Plate XVII.) 



Fronds up to 1 m. long; ultimate divisions up to 14 em long, 3 to 4 

 mm wide, more or less sinuate, obtuse, coriaceous, ash-green : sori some- 

 times copious, 2 mm in diameter. 



Borneo, Sarawak, around limestone caves at Niah and Bidi. 



10. CYATHEACE/K 



Caudex erect and almost always arborescent; fronds usually twice or 

 more pinnate; sori dorsal or marginal, glohose, with more or less prom- 

 inent receptacle; sporangia opening by a transverse slit, the annulus 

 (except exceptionally in Balantium) oblique enough to be a complete 

 ring. A family including one or two small genera besides those in this 

 region. Through Balantium, at least a part of the genera included here 

 are closely related to the Polypodiaceae. 



Sori dorsal 1. Cyathca 



Sori marginal. 



Fertile tooth slightly modified. 



Ultimate divisions oblique 2. Balantium 



Ultimate divisions not oblique 3. Dicksonia 



Fertile tooth greatly modified 4. Cibotium 



I. CYATHEA Smith. 



Tree ferns (with rare exceptions), often very large; sori on the backs 

 or in the forks of the fertile veinlets. These ferns are usually separated 

 artificially into three genera. Cyathca, Hemitelia or Amphicosmia, and 

 Alsophila. As construed here, Cyathca includes about 400 species, chiefly 

 tropical. 



1. Frond simple 1. C.sinuata 



1. Pinna; not lobed, not cordate 2. C. moluccana 



1. Pinna; lobed or almost entire, cordate 3. C. hookeri 



1. Pinnules not lobed. 



2. Pinnules less than 2 cm long 4. C. duHtensis 



2. Pinnules more than 3 cm long. 



3. Rachises glabrous 5. O. alternants 



3. Rachises finely hairy above. 



4. Sori not costular 6. C podophylfa 



4. Sori costular, crowded 7. C rhcosora 



