| 1 | Rhizome 5-20 mm ø, solenostelic, with an internal sclerotic Strand; rhizome scales to 7 mm long, the larger ones to c. 20-seriate at the base; spores trilete; sori of larger segments on (2-)5-8 vein-ends, occupying their whole apical margin (Fig. 5) |
| 1' | Rhizome 2-4 mm ø, with a lindsaeoid protostele; scales to 4 mm long, to 4-seriate at the base (wider in S. biflora); spores monolete; sori of larger segments on 1-2(-4) vein-ends, not occupying their whole apical margin. |
| 2 | Scales up to 3-seriate at the base; sori strictly uninerval; ultimate divisions 0.5-0.75 mm wide, or the fertile gradually widened to the sorus and there 1 mm wide; texture coriaceous. |
| 2' | Scales to 5-6-seriate at the gradually widened base; sori uni- or binerval; larger free ultimate divisions c. 2 mm wide; lamina subcoriaceous or coriaceous, usually bipinnate + pinnatifid or tripinnate + crenate |
| 2'' | Scales 1-3-seriate (or to 4-seriate at the suddenly broadened base); sori 1-3(-4)-nerval; larger free ultimate divisions 1 mm or more wide, or, if narrower, spathulately widened at the sorus; lamina herbaceous to subcoriaceous, in full-grown plants bipinnate + bipinnatifid, tripinnate + pinnatifid, or more dissected |
