The orchid Dendrobium Mary Trowse is a hybrid registered with the Royal Horticultural Society by Nakayama Bros. in 1954.
Top three species ancestors and their influences are

• Dendrobium schulleri (50.00%)  section: Spatulata 
• Dendrobium discolor (25.00%)  section: Spatulata 
• Dendrobium bigibbum var. superbum (12.50%)