'Weston's Crescendo' is a Diploid

Rhododendron 'Weston's Crescendo', which is a Mezitt hybrid documented as a Rhododendron minus hybrid, has been determined to be a diploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, 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.

Summary of Ploidy Levels

Diploid Rhododendron minus,
Diploid 'Manitou'
Diploid 'Weston's Crescendo'
Diploid 'Windbeam'

Source: John and Sally Perkins

John and Sally Perkins

'Frank Abbott' is a Diploid

Rhododendron 'Frank Abbott', which is a Ed Mezitt hybrid documented as Rhododendron molle hybrid x Rhododendron prinophyllum, has been determined to be a diploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, 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.

Frank Abbott started crossing Rhododendron prinophyllum and Rhododendron molle in the 1930's giving the best results of this cross the name Rhododendron 'Jane Abbott' after his daughter. When Ed Mezitt redid the cross thirty years later, Ed named one of his best results from the cross Rhododendron 'Frank Abbott'.

Rhododendron 'Frank Abbott' is rarely seed or pollen fertile. This lack of fertility may indicate that Rhododendron molle is not closely related to Rhododendron prinophyllum. Dr. Benjamin Hall's DNA has placed Rhododendron molle and Rhododendron prinophyllum in different clades and he suggests that Rhododendron molle DNA is closer to the tetraploid clade of deciduous azaleas than the diploid clade of deciduous azaleas.

Read Frank Abbott's Village of Azaleas"

Summary of Ploidy Levels

Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Frank Abbott',
Diploid "Jane Abbott" types

Source: John and Sally Perkins

John and Sally Perkins

'Blue Baron' is a Tetraploid

Rhododendron 'Blue Baron', which is a Mezitt hybrid documented as ['Starry Night' ('Gletschernacht') x 'Waltham'], has been determined to be a tetraploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, 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.

Some question whether Rhododendron 'Blue Baron' has Rhododendron 'Waltham' as the pollen parent.

Summary of Ploidy Levels

Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Purple Gem',
Tetraploid 'Blue Baron',
Tetraploid 'Blue Ridge',
Tetraploid 'Epoch',
Tetraploid 'Epoch' X Rhododendron augustinii,
Tetraploid "Medium Blue",
Tetraploid Rhododendron augustinii

Source: RareFind Nursery

John and Sally Perkins

'Magic' is a Tetraploid

Rhododendron 'Magic', which is a Mezitt Ghent, has been determined to be a tetraploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, 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.

Summary of Ploidy Levels

Tetraploid 'Magic'

Source: Planeview Nursery

John and Sally Perkins

'Deep Rose' is a Triploid

Rhododendron 'Deep Rose', which is an Ed Mezitt Ghent hybrid documented as Rhododendron arborescens (possibly cumberlandense) X red Ghent, 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.

To date all Ghents have tested as triploid or tetraploid.

Summary of Ploidy Levels

Diploid Rhododendron arborescens,
Diploid Rhododendron cumberlandense,
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Graf von Meran',
Triploid 'Josephine Klinger'

Source: George Hibben

John and Sally Perkins