1 | Rhizome with stiff, erect to pendent rootless aerial branches |
1' | Rhizome creeping |
2 | Fronds strongly dimorphic, scattered on the rhizome or somewhat clustered on short side branches |
2' | Fronds monomorphic or slightly dimorphic, often in whorls of 5-10 fronds |
3 | Lamina thick, coriaceous, costa below with copious, conspicuous, 3-4 mm long pale to brown scales |
3' | Lamina thin, papyraceous when dry, costa below mostly with few or inconspicuous scales |
4 | Rhizome in older parts not entirely covered with scales; scales with squarrose acumen and entire or distinctly glandular margin |
4' | Rhizome entirely covered with overlapping scales, scales with appressed or spreading apex, usually with non-glandular cilia |
5 | Rhizome scales with gradually narrowed apex, stipe 0.5-4.5 cm long, costa and stipe often with distinct dark coloration |
5' | Rhizome scales with abruptly narrowed apex, stipe to 2-3 mm long, costa and stipe without dark coloration below |
6 | Phyllopodia very short, inconspicuous, much shorter than the stipe, sori mostly in a closely costal single row |
6' | Phyllopodia longer, position of sori variable |