To confirm the registration of an Australian native hybrid & view its composition/progeny: (Database as at 1st January 2020 RHS registrations)
For non-Australian Dendrobium hybrids use the Dendrobium Hybrids checklist here
Sarco. Wanyin Marshmallows= Fitzhart x aequalis registered: 24/11/2019 by Chan K.Y. & S.W.
Species composition summary:
Sarco. Wanyin Marshmallows = Fitzhart x aequalis = [hartmannii x fitzgeraldii] x aequalis