The orchid Oncidium George McMahon is a hybrid registered with the Royal Horticultural Society by B.Cobbledick in 1989.
Top three species ancestors and their influences are

• Oncidium alexandrae (44.73%)
• Oncidium spectatissimum (17.38%)
• Oncidium luteopurpureum (13.23%)  subgenus Odontoglossum