Sect. Cyathea
Pinnules not over 30 mm. long; segments mostly constricted at base or the lower ones quite free
. . . . . . . . . . C. perpelvigera
Pinnules longer, or if under 30 mm. long without free basal segments
Indusium a complete firm dark open cup with even edge at maturity of sorus
. . . . . . . . . . C. pallidipaleata
Indusium otherwise or lacking
Indusium at maturity an almost flat brown disc, the residual part of a complete thin translucent indusium, the thin apical parts breaking and caducous at maturity
. . . . . . . . . . C. saccata
Indusium otherwise or lacking
Indusium covering sorus to maturity , then breaking and persistent
Costae and costules densely scaly; scales mostly setiferous, not bullate; pinna-rachis persistently covered with very small setiferous scales
. . . . . . . . . . C. inquinans
Costae and costules bearing scales which are mostly not setiferous; pinna-rachis glabrescent
. . . . . . . . . . C. oosora
Indusium hemitelioid (firm, brown, covering the sorus almost to maturity but open on side remote from costule)
. . . . . . . . . . C. oinops
Sect. Gymnosphaera
. . . . . . . . . . C. dimorpha
Subsect. Sphaeropteris
Indusium present
. . . . . . . . . . C. strigosa
Indusium lacking
Upper part of stipe and all rachises finely and very closely warty
. . . . . . . . . . C. elmeri
Upper part of stipe and rachises thorny or conspicuously warty, warts not very fine and close
Stipe conspicuously spiny; pale hairs on lower surface of costae few or lacking
. . . . . . . . . . C. tenggerensis
Stipe warty; pale hairs abundant on lower surface of distal half of costae and on costules
. . . . . . . . . . C. sarasinorum
Subsect. Fourniera
Bullate scales present on costae and costules
. . . . . . . . . . C. teysmannii
Bullate scales lacking
. . . . . . . . . . C. celebica
Subsect. Schizocaena
. . . . . . . . . . C. moluccana
