'Northern Starburst' is a Tetraploid

Rhododendron 'Northern Starburst', which is a Brigg's chemically treated 'PJM', 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

Diploid Rhododendron dauricum,
Diploid Rhododendron minus,
Tetraploid 'Northern Starburst'

Source: Rarefind Nursery

John and Sally Perkins

[Treated 'Nancy Evans'] X 'Point Defiance' is a Tetraploid

One seedling of [Briggs chemically treated Rhododendron 'Nancy Evans'] X Rhododendron 'Point Defiance', which was raised by Ned Brockenbrough, has been determined to be a tetraploid 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.

Summary of Ploidy Levels

Diploid 'Nancy Evans'
Tetraploid 'Point Defiance'
Tetraploid 1 Seedling of [treated 'Nancy Evans'] X 'Point Defiance'

Source: Ned Brockenbrough

John and Sally Perkins

'Brigg's Red Star' x 'Point Defiance' is a Tetraploid

Two seedlings of Rhododendron 'Brigg's Red Star' x 'Point Defiance', which were raised by Ned Brockenbrough, have been determined to be a tetraploid 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.

Summary of Ploidy Levels

Tetraploid 'Brigg's Red Star'
Tetraploid 'Point Defiance'
Tetraploid 2 Seedlings of 'Brigg's Red Star' x 'Point Defiance'

Source: Ned Brockenbrough

John and Sally Perkins

'Briggs Red Star' is a Tetraploid

Rhododendron 'Briggs Red Star', which is a chemically treated 'The Honourable Jean Marie de Montague' produced by Briggs, has been determined to be a tetraploid 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.

Ranney, Jones, and Lynch found 'Brigg's Red Star' to be a 2x + 4x mixaploid which breeds as a tetraploid having tetraploid pollen.

Summary of Ploidy Levels

Diploid 'The Honourable Jean Marie de Montague',
Tetraploid 'Brigg's Red Star'

Source: Ned Brockenbrough

John and Sally Perkins