| 1 | Dorsal outline of the frond round or elliptic. Ventral side inflated, globular. |
| 1' | Dorsal outline of the frond angular. Ventral side with a central conical protuberance |
| 2 | Dorsal outline of the frond elliptic. Dorsal side flat to convex. Width greatest below the dorsal plane, at ± half the height. |
| 2' | Dorsal outline of the frond round to ovate. Dorsal side flat. Width greatest in the dorsal plane |
