1 | Indusia rather large, persistent; lamina thin, veins slender, slightly prominent on both sides. |
1' | Indusia small, almost hidden by sporangia at maturity of sorus, or apparently lacking; lamina firm, veins not prominent on either.surface. |
2 | Caudex long-creeping; pinnae lobed half-way to costa or less deeply; apex of frond ± pinna-like |
2' | Caudex short-creeping or erect; pinnae lobed more than half-way to costa; apex of frond not pinna-like. |
3 | Pinnae lobed to 1 mm from costa or more deeply; basal veins free or uniting to form very short excurrent veins. |
3' | Pinnae lobed less deeply; basal veins anastomosing to form an excurrent vein on most parts of a frond |
4 | Basal veins not meeting; sori in slight depressions |
4' | Basal veins meeting just below the sinus, sometimes forming a short excurrent vein; sori not immersed |
5 | Hairs more than 0.5 mm long present on both sides of costa; stipe and abaxial surface of rachis bearing scales throughout |
5' | All hairs on costa very short; scales confined to base of stipe. |
6 | Lower surface between veins (sometimes in part) bearing very short erect acicular hairs; short capitate hairs also in this position on the upper surface |
6' | Both surfaces lacking hairs between veins. |
7 | Pinnae lobed to c. 2 mm from costa, basal veins often anastomosing. |
7' | Pinnae lobed more deeply; basal veins not anastomosing. |
8 | Many glandular hairs on lower surface between veins, some spherical, some ± elongate; similar hairs also on indusia |
8' | Glandularhairs less abundant, always spherical, tending to collapse and form resinous patches or to disappear on drying |
9 | Pinnae thin, to 3 cm wide; glands on lower surface of pinnae and on indusia elongate |
9' | Pinnae firm, to 1.5 cm wide; glands on lower surface glabular to pyriform, on indusia spherical, resinous |