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. Perky= hartmannii x spathulatus ( has 5 hybrid progeny ) registered: 1/11/1972 by Butler I.A.
Species composition summary:
Sarco. Perky = hartmannii x spathulatus