1 Pinnae dichotomously forked

1 Pinnae simple.

..2 Scales of the petiole appressed, strongly bicolored (the central portion shining dark brown or blackish, with wide and well-developed hyaline margins).

....3 Upper side of the costae densely hairy with pale hairs 0.1-0.5 mm long; scales of the upper surface of the rachis hyaline or light brown, the acumen entire or nearly so; sori submedial

....3 Upper side of the costae glabrous; scales of the upper surface of the rachis rufous, the acumen strongly dentate; sori submarginal

..2 Scales of the petiole spreading or loose, nearly mono-colored (reddish, light brown, or tan, hyaline margins absent or narrow and indistinct).

......4 Upper side of the costae sparsely to densely hairy with hairs 0.2-0.6 mm long; pinnae 2.5-23 cm long, not distinctly auricled at the base.

........5 Upper side of the costae sparsely hairy, the hairs 0.4-0.6 mm long; pinnae mostly falcate

........5 Upper side of the costae densely hairy, the hairs 0.2-0.4 mm long; pinnae mostly not falcate

......4 Upper side of the costae glabrous; pinnae 1-7.3 cm long, auricled at base on the side toward the leaf tip.

..........6 Scales on the upper surface of the rachis bicolored (pale but distinctly darker at the base); pinnae attachments spaced 5-12 mm apart; leaf blade with an obtuse apex; underside of rachis almost completely hidden by the overlapping basal lobes of the pinnae; rhizomes bearing spherical tubers (not always present)

..........6 Scales on the upper surface of the rachis concolored (pale to reddish brown throughout); pinnae attachments spaced 7-21 mm apart; leaf blade with an acute to acuminate apex; underside of rachis not or only slightly obscured by the pinna blades; rhizomes not bearing tubers