To confirm the registration of an Australian native hybrid & view its composition/progeny: (Database as at 1st April 2018 RHS registrations)
For non-Australian Dendrobium hybrids use the Dendrobium Hybrids checklist here
Sarco. Star Struck= Southern Cross x fitzgeraldii ( has 14 hybrid progeny ) registered: 1/01/1989 by Harris R.E.
Species composition summary:
Sarco. Star Struck = Southern Cross x fitzgeraldii = [hartmannii x australis] x fitzgeraldii