Rhododendron 'Solidarity', which is a Hank Schannen hybrid documented as R. degronianum ssp. yakushimanum X 'The Honorable Jean Marie de Montague', has been determined to be a triploid using flow cytometry by
Dr. João Loureiro, Dr. Silvia Castro, José Cerca, and Mariana Castro
Plant Ecology and Evolution Group,
Centre for Functional Ecology,
Department of Life Sciences,
Faculty of Science and Technology,
University of Coimbra, Portugal.
Rhododendron 'Solidarity' is known, on occasion, to produce open pollinated seedpods and this seed will sometimes germinate.
Rhododendron 'The Honorable Jean Marie de Montague', although a diploid, is documented as the parent of several triploids indicating 'The Honorable Jean Marie de Montague' may throw more unreduced gametes than most diploids.
Rhododendron 'Anita Gehnrich', which is documented as the reverse cross of 'Solidarity, is also a triploid.
Summary of Ploidy Levels
Diploid 'The Honorable Jean Marie de Montague',
Triploid 'Anita Gehnrich',
Triploid 'Solidarity'
Source: Werner Brack
John and Sally Perkins
