1 | Sori 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 |
2 | Foliage fronds pinnatifid |
2' | Foliage fronds pinnate |
3 | Rhizome scales spreading, without midrib in the acumen |
3' | Rhizome scales appressed or with a narrow, squarrose acumen with a distinct midrib |
4 | Base fronds margin sinuate to distinctly lobed |
4' | Base fronds entire to shallowly sinuate |
5 | Foliage 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 |
6 | Base 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 |