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
Den. Hilda Poxon
= speciosum x tetragonum ( has 70 hybrid progeny ) registered: 1/01/1977 by Grundon N. -ButlerANOS judging segment: Australian (Section Dendrocoryne ) Den. Hilda Poxon 'Patricia' AM/ANOS 2017 Photo W. Dobson

Species composition summary:
tetragonum 50.% speciosum 50.%
Detailed composition:
Den. Hilda Poxon = speciosum x tetragonum