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. Starhart= Star Struck x hartmannii ( has 1 hybrid progeny ) registered: 26/01/2000 by Roper N.
Species composition summary:
hartmannii 62.5% fitzgeraldii 25.% australis 12.5%
Sarco. Starhart = Star Struck x hartmannii = [Southern Cross x fitzgeraldii] x hartmannii
Southern Cross = hartmannii x australis