KEY TO THE SPECIES

1Scales on pinna-rachis narrow with inflexed edges or flat, their bases sometimes widened but not cordate nor point- attached; isodiametric cells few, near base.
1'Scales on pinna-rachis flat or nearly so, point- attached at a deeply cordate base; many isodiametric cells in their basal part
2Basal basiscopic pinnules of basal pinnae not longest, less than twice as long as the basal acroscopic pinnules
2'Basal basiscopic pinnules of basal pinnae distincdy longer than the rest, usually twice as long as acroscopic ones
3Veins thick and prominent on lower surface
3'Veins not prominent on lower surface, the smaller ones in many cases indistinct
4Tertiary leaflets 3x3 mm, almost entire, their upper surface densely covered with short hairs
4'Tertiary leaflets, if present, differently shaped and not thus covered
5Pinnules or lobes of middle pinnae not lobed nearly to their costae; spreading bristle- like scales present throughout the main rachis
5'Pinnules or lobes of middle pinnae lobed nearly to their costae; such scales not present
6Scales on pinna-rachis flat or nearly so
6'Scales on pinna-rachis with inflexed edges, at least near their bases
7Scales on pinna-rachis not widened at their bases; isodiametric cells at base few; costal scales very narrow
7'Scales on pinna-rachis widened at their bases, the widened part consisting entirely of isodiametric cells; costal scales with broad base
8Stipe densely scaly throughout, scales at top of stipe 10 mm long
8'Stipe densely scaly near base only; distal scales 3 mm long.
9Lamina opaque; smaller veins not distinct on lower surface.
9'Lamina not opaque; veins distinct
10Scales on pinna-rachis very thin, few cells wide, lacking conspicuous isodiametric cells
10'Scales on pinna-rachis wider with reflexed margins, widened at their bases with some isodiametric cells
11Indusium very small, hidden by sporangia at maturity, bearing long slender flexuous glands
11'Indusium distinct but fragile, not long-fringed
12Basal basiscopic tertiary divisions of basal pinnae lobed
12'Basal basiscopic tertiary divisions of basal pinnae entire
13Pinnae narrowly acuminate; appressed glands present on upper surface
13'Pinnae not narrowly acuminate; short erect capitate hairs present between veins on upper surface
14Free pinnae to 8 pairs; basal pinnae of mature plants shorter than suprabasal ones
14'Free pinnae to c. 4 pairs; basal pinnae longer than suprabasal ones
15Lobes of middle pinnae mostly subentire with rounded apices
15'Lobes of middle pinnae mostly lobulate, their apices not rounded
16Lamina to 13 cm long, bearing many suberect hairs between veins on upper surface
16'Lamina much longer; hairs on upper surface appressed.
17Tertiary leaflets of basal pinnae quite free, lobed to their costules, their basal lobes lobulate
17'Tertiary leaflets of basal pinnae adnate and less deeply lobed, their lobes entire.
18Lobes of tertiary leaflets of basal pinnae deeply lobulate; thick cylindric glands copi ous on upper surface
18'Lobes of tertiary leaflets of basal pinnae not deeply lobulate; appressed glands on upper surface neither thick nor copious
19Basal pinnae to 60 cm long
19'Basal pinnae to 25 cm long
20Lobules or lobes of middle pinnae acute
20'Lobules or lobes of middle pinnae not acute
21Basal tertiary leaflets lobed almost to their costules, lobes to 6 pairs.
21'Basal tertiary leaflets lobed less deeply with fewer lobes
22Lamina to 60 cm long; basal pinnae more than 20 cm
22'Lamina rarely more than 35 cm long; basal pinna to 15 cm
23Costules of basal basiscopic lobes of upper pinnae arising from the main rachis
23'Costules of basal basiscopic lobes of upper pinnae arising from costae of pinnae
24Basal basiscopic pinnules of basal pinnae about twice as long as acroscopic ones.
24'Basal basiscopic pinnules of basal pinnae much less than twice as long as acroscopic ones
25Tertiary leaflets of basal pinnae deeply lobed at their bases
25'Tertiary leaflets of basal pinnae lobed less than halfway to their costules
26Tertiary leaflets to 18 × 10 mm; scales on rachis very narrow, not stiffly spreading
26'Tertiary leaflets to 8 × 4 mm; scales on rachis stiffly spreading
27Tertiary leaflets of basal pinnae and lobes of distal pinnae widely spaced, narrow, falcate
27'Tertiary leaflets of basal pinnae and lobes of distal pinnae almost contiguous