Sect. Cyathea
Indusium at maturity an almost flat disc, symmetric or not, in some cases hidden by mature sorus, in some cases the residual part of a complete indusium of which the thin apical parts fall away at maturity
Indusium at maturity a disc with fairly even edge (except in C. patellifera)
Pinnules to at least 85 x 20 mm; veins 8-10 pairs
Pinna-rachis and costae densely hairy on lower surface; costae glabrous or nearly so on upper surface
. . . . . . . . . . C. javanica
Pinna-rachis hairy towards apex only; costae with few hairs on lower surface, many on upper surface
. . . . . . . . . . C. hymenodes
Pinnules about 30-70 x 12-15 mm; veins 4-6 pairs
. . . . . . . . . . C. patellifera
Indusium at first covering sorus, apical part very thin and caducous, an irregular disc remaining on old sorus
Pinna-rachis hairy on lower surface, at least distally
. . . . . . . . . . C. sumatrana
Pinna-rachis not hairy on lower surface
Small pale fringed scales abundant at least on costae
. . . . . . . . . . C. trachypoda
Small pale fringed scales lacking or very few
Stipe bearing spines 3-5 mm long
Larger scales on costae bearing dark setae
. . . . . . . . . . C. macropoda
Larger scales on costae not bearing dark setae
. . . . . . . . . . C. magnifolia
Stipe not spiny, or spines under 1 mm long
. . . . . . . . . . C. excavata
Indusium otherwise or lacking
Pinna-rachis densely hairy throughout on lower surface
Raised median part of upper surface of pinna-rachis and costae hairy
. . . . . . . . . . C. modesta
Raised median part of upper surface of pinna-rachis and costae glabrous
. . . . . . . . . . C. doctersii
Pinna-rachis hairy at most on distal parts
Indusium entirely brown and rather firm, quite covering sorus to maturity, breaking only when old
. . . . . . . . . . C. oinops
Indusium in part pale and fragile, breaking at maturity, or not entirely covering sorus
Indusium visible as a scale backing the costule, not entirely hidden by sorus
Pinnules conspicuously stalked; stalks to 7 mm long
. . . . . . . . . . C. loerzingii
Pinnules not conspicuously stalked
Basal scales on costae bearing some marginal setae
. . . . . . . . . . C. costulisora
Basal scales on costae without setae
Bullate scales present (if at all) towards apex of costa; costal scales few; pinnules to 100 mm long
. . . . . . . . . . C. junghuhniana
Bullate scales abundant to base of costae and on costules; pinnules to 65 mm long
. . . . . . . . . . C. raciborskii
Indusium very small, hidden by sporangia
Pinnules commonly more than 20 mm wide
. . . . . . . . . . C. punctulata
Pinnules commonly not more than 20 mm wide
Pinnules articulate to pinna-rachis
. . . . . . . . . . C. perpunctulata
Pinnules not articulate
Paraphyses conspicuous, longer than sporangia, 2-3 cells wide at base
Stipe-spines 3-4 mm long; pinna-rachis hairy towards apex on lower surface
. . . . . . . . . . C. alderwereltii
Stipe-spines 1-2.5 mm long; pinna-rachis not hairy on lower surface
. . . . . . . . . . C. latebrosa
Paraphyses shorter than sporangia, slender
. . . . . . . . . . C. junghuhniana
Sect. Gymnosphaera
Reduced pinnae present at base of stipe, separated from normal pinnae
. . . . . . . . . . C. recommutata
Reduced pinnae, separate from the rest, lacking; lower pinnae in some cases reduced gradually almost to base of stipe, the lowest sometimes with narrow segments
Pinnules almost entire
. . . . . . . . . . C. glabra
Pinnules distinctly lobed
Scales on lower surface of costules bullate
. . . . . . . . . . C. lurida
Scales on lower surface of costules not bullate
Scales on costae bearing lateral setae; segments or lobes of pinnules rounded and subentire; sori usually not converging towards apices of segments; basal basiscopic vein from costule
Stipe and basal part of rachis persistently scaly; largest pinnules with stalks at most 2 mm; veins to 6 pairs
. . . . . . . . . . C. subdubia
Persistent large scales only at base of stipe; largest pinnules with stalks to 4 mm; veins 3-5 pairs
. . . . . . . . . . C. glabra
Scales on costae lacking lateral setae; segments of lamina deltoid and distinctly toothed; sori converging towards apices of segments; basal basiscopic vein often from costa
. . . . . . . . . . C. gigantea
Subsect. Sphaeropteris
Bullate scales present on lower surface of costae and costules
. . . . . . . . . . C. persquamulifera
Bullate scales lacking on lower surface of costae and costules
. . . . . . . . . . C. verrucosa
Subsect. Schizocaena
Fronds simply pinnate, pinnae entire
. . . . . . . . . . C. moluccana
Fronds simply pinnate with deeply lobed pinnae, or bipinnate
Fronds simply pinnate with deeply lobed pinnae, the largest sometimes with free pinnules at their base
Lower surface of pinna-midribs covered near base with long hairs; no free pinnules
. . . . . . . . . . C. deminuens
Lower surface of pinna-midrib lacking hairs; some free pinnules on largest pinnae
. . . . . . . . . . C. alternans
Fronds amply bipinnate
Pinnules entire or with crenate edges
. . . . . . . . . . C. alternans
Pinnules distinctly lobed
Sori indusiate
Copious long hairs on lower surface of veins as well as costules
. . . . . . . . . . C. senex
No hairs on lower surface of veins
. . . . . . . . . . C. assimilis
Sori without indusia
Sori on 3-4 pairs of basal veins in each group only, not on distal veins, at maturity confluent
. . . . . . . . . . C. obscura
Sori on almost all veins, not confluent at maturity
. . . . . . . . . . C. squamulata
