KEY TO THE SUBDIVISION OF THE GENUS CYATHEA IN
AUSTRALASIA AND THE PACIFIC
Stipe-scales firm, with fragile edges which are often abraded when old; deeply excavated pneumathodes arranged as V below base of each stipe
. . . . . . . . . . Subgenus CYATHEA
Indusia present (sometimes hidden by sporangia) in almost all cases; axes of frond not very dark; little difference in size between fertile and sterile leaflets; larger scales on pinnules often lacking dark median band
. . . . . . . . . . Section Cyathea
Indusia lacking; axes of frond very dark; fertile pinnules contracted as compared with sterile; larger scales on pinnules always with dark median band
. . . . . . . . . . Section Gymnosphaera
Stipe-scales (at least in their distal part) having cells uniform throughout, their marginal cells, or some of them, bearing thick-walled oblique setae; deeply excavated pneumathodes lacking below stipe-bases
. . . . . . . . . . Subgenus SPHAEROPTERIS
Costules not widely spaced (rarely over 4 mm. apart in pinnules 10 cm. long); pinnules lobed almost or quite to costa throughout, or fully pinnate; basal basiscopic vein of each group usually not springing directly from costa; pinna-rachis usually warty on lower surface
. . . . . . . . . . Section Sphaeropteris
Stipe and rachis not very dark, usually glabrescent above base of stipe; sori indusiate or not, in the latter case sometimes bearing narrow scales spreading around base of receptacle
. . . . . . . . . . Subsection Sphaeropteris
Stipe and rachis very dark, bearing many small scales which have dark setae; pinnules mostly fully pinnate; sori protected by overlapping thin scales, not by indusia
. . . . . . . . . . . Subsection Fourniera
Costules commonly 5-6 mm. apart except on small pinnules; pinnules not lobed to within 1 mm. of costa; basal basiscopic vein of a group always springing from costa; pinna-rachis smooth
. . . . . . . . . . . Section Schizocaena
AUSTRAL Is. (3 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. stokesii
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
. . . . . . . . . . C. affinis
Subsect. Sphaeropteris
. . . . . . . . . . C. medullaris
AUSTRALIA (10 species)
Sect. Cyathea
Indusium absent
. . . . . . . . . . C. australis
Indusium present
Lamina segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. robertsiana
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
Very small scales bearing long stiff pale hairs or dark setae abundant on lower surface of costae
. . . . . . . . . . C. cunninghamii
Very small scales of this kind lacking
Indusium small, hidden by mature sporangia
. . . . . . . . . . C. woollsiana
Indusium conspicuous
. . . . . . . . . . C. marcescens
Sect. Gymnosphaera
Reduced pinnae lacking lamina (restricted to veins) present at base of stipe
. . . . . . . . . . C. baileyana
Lower pinnae gradually reduced, lowest with normal lamina
. . . . . . . . . . C. rebeccae
Subsect. Sphaeropteris
. . . . . . . . . . C. cooperi
Subsect. Fourniera
Lower surface of veins bearing finely-fringed interlacing scales which cover lower surface of leaflets
. . . . . . . . . . C. celebica
Lower surface of veins bearing at most scattered small scales
. . . . . . . . . . C. leichardtiana
CAROLINE Is. (2 species)
Subsect. Sphaeropteris
Sori indusiate
. . . . . . . . . . C. nigricans
Sori lacking indusia, often with small scales around base of receptacle
. . . . . . . . . . C. lunulata
COOK Is. (3 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. decurrens
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
. . . . . . . . . . C. affinis
Subsect. Sphaeropteris
. . . . . . . . . . C. parksiae
FIJI (11 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. decurrens
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
Bullate scales abundant on costules
. . . . . . . . . . C. alta
Bullate scales lacking on costae and costules
Pinnules to 7.5 cm. long, veins to 8-9 pairs; no scales on lower surface of veins; indusium firm, reflexed at maturity
. . . . . . . . . . C. plagiostegia
Pinnules commonly 10 cm. long, veins 10-14 pairs; small scales present on lower surface of veins; indusium thin, larger, not wholly reflexed at maturity
. . . . . . . . . . C. affinis
Sect. Gymnosphaera
. . . . . . . . . . C. hornei
Subsect. Sphaeropteris
Sori indusiate
. . . . . . . . . . C. medullaris
Sori lacking indusia, often with small scales around base of receptacle
. . . . . . . . . . C. lunulata subsp. vitiensis
Subsect. Fourniera
. . . . . . . . . . C. truncata
Sect. Schizocaena
Pinnules 3-4 cm. long; veins 3-5 pairs
. . . . . . . . . . C. subsessilis
Pinnules commonly to 10 cm. long; veins 8-10 pairs
Stipe to 60 cm. long; lower pinnae not greatly reduced; scales on costae mostly bearing close short marginal setae; no bullate scales
. . . . . . . . . . C. microlepidota
Stipe 10-25 cm. long; basal pinnae 10 cm. or less; scales on costae with sparse lateral setae or none; bullate scales usually present
. . . . . . . . . . C. propinqua
KERMADEC Is. (2 species)
Sect. Cyathea
Indusium at first covering the sorus completely, its base completely surrounding the receptacle
. . . . . . . . . . C. milnei
Indusium open on side of receptacle remote from costule, its base never forming a complete cup around receptacle
. . . . . . . . . . C. kermadacensis
LORD HOWE Is. (4 species)
Sect. Cyathea
Pinna-rachis covered beneath with crisped hairs or hair-like scales which are not setiferous
. . . . . . . . . . C. macarthurii
Pinna-rachis covered beneath with small scales, many of them bearing dark setae
Paraphyses thick, pale, much longer than sporangia
. . . . . . . . . . C. howeana
Paraphyses not longer than sporangia
. . . . . . . . . . C. brevipinna
Subsect. Sphaeropteris
. . . . . . . . . . C. robusta
MARIANAS (2 species)
Subsect. Sphaeropteris
Bullate scales present on costae and costules
. . . . . . . . . . C. lunulata
Bullate scales lacking on costae and costules
. . . . . . . . . . C. aramaganensis
MARQUESAS (3 species)
Sect. Cyathea
. . . . . . . . . . C. affinis
Subsect. Sphaeropteris
Stipe-scales pale; narrow scales with long marginal setae or hairs on lower surface of costae and costules, these scales grading distally to long hairs; a few long pale hairs on upper surface of costules
. . . . . . . . . . C. feani
Stipe-scales dark brown; costal scales ovate-acute with long setae or marginal hairs; pale hairs lacking on both surfaces of costules
. . . . . . . . . . C. medullaris
NEW CALEDONIA (7 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. alata
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
Bullate scales abundant on costules
. . . . . . . . . . C. stelligera
Bullate scales lacking on costae and costules
. . . . . . . . . . C. vieillardii
Subsect. Sphaeropteris
Sori indusiate
. . . . . . . . . . C. albifrons
Sori lacking indusia, often with small scales around base of receptacle
Large pale bullate scales present on costules
. . . . . . . . . . C. lunulata
Bullate scales lacking on costae and costules
. . . . . . . . . . C. intermedia
Subsect. Fourniera
. . . . . . . . . . C. novae-caledoniae
NEW ZEALAND (5 species)
Sect. Cyathea
Indusium absent
. . . . . . . . . . C. colensoi
Indusium present
Indusium at first covering the sorus completely, its base completely surrounding the receptacle
. . . . . . . . . . C. dealbata
Indusium open on side of receptacle remote from costule, its base never forming a complete cup around receptacle
Pinnules to 2.5 cm. wide; indusium quite covering sorus to maturity, then breaking
. . . . . . . . . . C. cunninghamii
Pinnules to 1.8 cm. wide; indusium reflexed at maturity, not splitting
. . . . . . . . . . C. smithii
Subsect. Sphaeropteris
. . . . . . . . . . C. medullaris
NORFOLK Is. (2 species)
Sect. Cyathea
. . . . . . . . . . C. australis subsp. norfolkensis
Subsect. Sphaeropteris
. . . . . . . . . . C. brownii
PITCAIRN Is. (1 species)
Subsect. Sphaeropteris
. . . . . . . . . . C. medullaris
SAMOA (10 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
Pinnules to 13 x 3 cm; costules 4½ - 6 mm. apart; lobules crenulate near apices
. . . . . . . . . . C. decurrens
Pinnules to 14 x 4 cm; costules to 7 mm. apart; lobules of lamina-segments rather deeply lobed
. . . . . . . . . . C. decurrens var. vaupelii
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
Bullate scales abundant on costules
. . . . . . . . . . C. alta
Bullate scales lacking on costae and costules
. . . . . . . . . . C. affinis
Subsect. Sphaeropteris
Sori indusiate
Bullate scales present on costules; pinna-rachis smooth beneath
. . . . . . . . . . C. whitmeei
Bullate scales lacking; pinna-rachis copiously warty beneath (except on distal pinnae)
. . . . . . . . . . C. medullaris
Sori lacking indusia, often with small scales around base of receptacle
. . . . . . . . . . C. lunulata
Subsect. Fourniera
. . . . . . . . . . C. truncata
Sect. Schizocaena
Pinnules 3-4 cm. long; veins 3-5 pairs
. . . . . . . . . . C. subsessilis
Pinnules commonly to 10 cm. long; veins 8-10 pairs
. . . . . . . . . . C. vaupelii
SOLOMON Is. (8 species)
Sect. Cyathea
Bullate scales abundant on costules
. . . . . . . . . . C. alta
Bullate scales lacking on costae and costules
. . . . . . . . . . C. solomonensis
Subsect. Sphaeropteris
Sori indusiate
. . . . . . . . . . C. whitmeei
Sori lacking indusia, often with small scales around base of receptacle
Bullate scales abundant on lower surface of veins; stipe-scales to 15x3 mm, very thin
. . . . . . . . . . C. vittata
Bullate scales lacking or rare on lower surface of veins; stipe-scales mostly longer and proportionately narrower
. . . . . . . . . . C. lunulata
Subsect. Fourniera
Soral scales small, not covering sorus to maturity
. . . . . . . . . . C. truncata
Soral scales large, covering sorus to maturity
. . . . . . . . . . C. aciculosa
Sect. Schizocaena
. . . . . . . . . . C. brackenridgei
TAHITI (3 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. decurrens
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
. . . . . . . . . . C. affinis
Subsect. Sphaeropteris
. . . . . . . . . . C. medullaris
TONGA (1 species)
Subsect. Sphaeropteris
. . . . . . . . . . C. lunulata
VANUATU (5 species)
Sect. Cyathea
Lamina-segments, both sterile and fertile, lobed at least ½ way to costule; veins often pinnate in the lobes
. . . . . . . . . . C. decurrens
Sterile lamina-segments not deeply lobed; lateral veins in segments not pinnate
Axes of frond very dark; hairs present towards apices of costae and on costules on lower surface
. . . . . . . . . . C. aneitensis
Axes of frond pale; hairs often present on pinna-rachis and bases of costae, rarely on lower surface of costules
. . . . . . . . . . C. vieillardii
Subsect. Sphaeropteris
. . . . . . . . . . C. lunulata
Sect. Schizocaena
. . . . . . . . . . C. leucolepis
