Sorry I can't help, just giving a
Only thing I would say is that people often refer to a
type but that does not mean it's that species but rather a close related one.
Orchid Genuses are split in many cases into sub-genuses and many sub-genuses tend to be named after a species. For example Den phal
type indicates a sub-genus of Dendrobium which is named after the species phalaenopsis (since renamed but the sub-genus remains the same).
I don't know for certain but I wonder if the same is true of this and that there is a sub-genus of johnsonii.