Okay guys. I remember doing this before but I'll do it again!
Dendrobium anosmum used to be Dendrobium superbum. So really superbum should not be used any more.
Dendrobium aphyllum is now the proper name for Dendrobium pierardii.
Den. Nestor is Dendrobium parishii X Dendrobium anosmum. Labeling it as Dendrobium parishii X Dendrobium superbum would not be correct.
I should note that anosmum, aphyllum and parishii all have species rank!
Why are there synonyms? Usually a name is changed because the authorities have found an older, published viable name for a species. For example, Dendrobium pierardii is now Dendrobium aphyllum because they found Dendrobium aphyllum to be an older, valid published name for that species.
