| 1 | Veins always simple except sometimes in basal acroscopic lobes of pinnae. |
| 1' | Veins normally forked except distal ones. |
| 2 | Pinnae with some hairs on lower surface between veins; lobes of larger pinnae lobed more than half way to costule |
| 2' | Pinnae not hairy between veins on lower surface; pinna-lobes entire to crenate, shallowly lobed only on largest fronds. |
| 3 | Pinnae rarely over 6 cm long; indusia bearing acicular hairs |
| 3' | Pinnae of well-grown plants 12 cm or more long; indusia bearing capitate hairs. |
| 4 | Lower surface of costae and costules bearing copious capitate hairs. |
| 4' | Lower surfaces of costae and costules bearing sparse acicular hairs |
| 5 | Texture thin, drying dark green; veins conspicuously branched. |
| 5' | Texture firm, drying yellow-green; veins forked near tips, branches little diverging |
