Calyx fusion

Where the calyx and corolla are not clearly differentiated, use the corolla characters for the perianth.

The fusion of the calyx, as exhibited by the flower at anthesis. If an hypanthium is developed the calyx lobes are regarded as fused but they are also regarded as free if they are attached separately to the hypanthium. This may detract from the scientific merit of the system but should avoid confusion if an observer is not familiar with the concept of an hypanthium.