'Hank's Folly' is a Triploid

Rhododendron 'Hank's Folly', which is a Hank Schannen hybrid documented as 'Chionoides' x 'Gibraltar', 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.

'Hank's Folly' is a cross of an elepidote with a deciduous azalea.

'Gibraltar' has been determined to be a tetraploid using flow cytometry by Dr. Thomas Ranney, J.R. Jones, and Nathan Lynch.

Summary of Ploidy Levels

Triploid 'Hank's Folly',
Tetraploid 'Gibraltar'

Source: Rarefind Nursery

John and Sally Perkins

'Solidarity' is a Fertile Triploid

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