| 1 | Pinnules 5 times or more as long as broad, 3-4 mm wide (apart from basal auricles), with contiguous bases |
| 1' | Pinnules relatively much shorter, or, if up to 5 times as long as wide, 8 mm wide (apart from basal auricles) and at least in the basal half of the lamina not contiguous. |
| 2 | Pinnules suborbicular, not more than 1 mm longer than broad, coriaceous, not auricled; rachis black, lustrous |
| 2' | Pinnules ovate to lanceolate, the difference between length and width greater; at least some pinnules distinctly auricled; rachis brown to black, lustrous or not. |
| 3 | Rachis blackish, lustrous, abaxially keeled to the base; upper pinnules little or not reduced, terminal division free |
| 3' | Rachis not blackish and lustrous, or, if so, not keeled to the base; upper pinnules reduced, some confluent with the terminal segment. |
| 4 | Rachis dull, medium to dark reddish brown, rarely darker or lustrous; pinnules obtuse or rarely subacute, the larger ones 7-18 mm long, up to 2½ times as long as wide. |
| 4' | Rachis lustrous, reddish to dark brown; pinnules obtuse, the larger ones 5-8 mm long, less than 1½ times as long as wide |
| 4'' | Rachis dull, dark brown; pinnules acute or rarely subacute, the larger ones 18-30 mm long, to 4 times as long as wide |
