1Fertile parts strongly contracted
1'Fertile parts similar to sterile part or narrowed
2Rhizome scales with a narrow, subulate, entire acumen
2'Rhizome scales with acumen not narrow, subulate
3Sori slightly or deeply sunken
3'Sori superficial
4Rhizome scales strongly dentate, sori round or longitudinally elongate.
4'Rhizome scales entire to short-dentate, sori round or forming transverse coenosori
5Hydathodes absent, margin of sterile fronds with notches sporadically to regularly present, sori round
5'Hydathodes frequent, margin of sterile fronds without notches, sori in transverse coenosori
6Sori round or elongated, not forming coenosori crossing the veins
6'Sori forming long, sometimes interrupted coenosori, usually across the veins
7Rhizome scales remotely and weakly dentate, hydathodes constantly present, notches in fertile fronds sporadically present
7'Rhizome scales strongly dentate, hydathodes absent or occasionally present, notches in fertile fronds absent
8Rhizome scales pseudopeltate, sclerenchyma strands in the rhizome few, costa only distinct
8'Rhizome scales peltate, sclerenchyma strands in the rhizome many, veins distinct
9Upper surface of lamina not glandular
9'Upper surfaces of lamina distinctly glandular
10Fronds pinnatifid or pinnate
10'Fronds simple or trilobed
11Fronds pinnatifid
11'Fronds fully pinnate
12Calcareous scales persistent, margin of fronds without notches.
12'Calcareous scales not persistent, notches regularly present
13Pinnae inserted more or less transverse to the rachis, rhizome with few, inconspicuous sclerenchyma strands, scales shiny
13'Pinnae in the same plane with the rachis, rhizome with many sclerenchyma strands, rhizome scales dull
14Rhizome scales strongly dentate at least at their base, basal pinnae cut to midrib on basiscopic side
14'Rhizome scales entire or weakly dentate, basal pinnae with equal base or cut to midrib on acroscopic side
15Sori in two or more rows between adjacent veins
15'Sori in one row between adjacent veins
16Hydathodes frequent
16'Hydathodes absent
17Rhizome scales entire, internodes to 2.5 cm long
17'Rhizome scales short-dentate to strongly dentate, internodes to c. 1 cm long.
18Rhizome scales pseudopeltate, rhizome short, phyllopods mostly nearly contiguous
18'Rhizome scales peltate, rhizome short-creeping, phyllopods distinctly spaced.