KEY TO THE SPECIES

1Sori in a single row between the veins, rhizome with sclerenchyma strands
1'Sori in two or more rows between the veins, rhizome without sclerenchyma strands
2Foliage fronds pinnatifid
2'Foliage fronds pinnate
3Rhizome scales spreading, without midrib in the acumen
3'Rhizome scales appressed or with a narrow, squarrose acumen with a distinct midrib
4Base fronds margin sinuate to distinctly lobed
4'Base fronds entire to shallowly sinuate
5Foliage pinnae without basal constriction, 1-2.5 cm wide, apex obtuse to acute.
5'Foliage pinnae with a basal constriction, 2.5-4 cm wide, apex acute to acumi- nate
6Base fronds overlapping, completely covering the rhizome, rhizome to 3 cm thick, thickened midrib in the acumen of the rhizome scales brown, free veinlets simple or absent
6'Base fronds spaced, usually not completely covering the rhizome, rhizome to 1 cm thick, midrib in the acumen of the rhizome scales black, free veinlets simple or forked