'Ramapo' is a Fertile Triploid

Rhododendron 'Ramapo', which is a Guy Nearing hybrid documented as Rhododendron minus Carolinianum Group x Rhododendron fastigiatum, has been determined to be a triploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, 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.

'Ramapo' is documented to be the seed parent of the triploid 'Ramolet'.

Summary of Ploidy Levels

Diploid Rhododendron minus,
Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Purple Gem',
Triploid 'Ramapo',
Triploid 'Ramolet'

Source: John and Sally Perkins

John and Sally Perkins

'Spicy Lights' is a Triploid

Rhododendron 'Spicy Lights', which is in the Northern Lights group from the University of Minnesota documented as Rhododendron prinophyllum as the seed parent, has been determined to be a triploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, 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 'Spicy Lights' appears to be sterile.

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Lilac Lights',
Diploid 'Orchid Lights',
Diploid 'Rosy Lights',
Triploid 'Spicy Lights',
Triploid 'White Lights',
Tetraploid Rhododendron atlanticum,
Tetraploid Rhododendron calendulaceum,
Tetraploid Rhododendron luteum,
Tetraploid 'Apricot Surprise',
Tetraploid 'Candy Lights',
Tetraploid 'Golden Lights',
Tetraploid 'Lemon Lights',
Tetraploid 'Mandarin Lights',
Tetraploid 'Northern Hi-Lights',
Tetraploid 'Tri-Lights'

Source: Kristian Theqvist

John and Sally Perkins

'White Lights' is a Triploid

Rhododendron 'White Lights', which is in the Northern Lights group from the University of Minnesota documented as Rhododendron prinophyllum X white Exbury, has been determined to be a triploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, 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 'White Lights' appears to be sterile.

Most Exbury deciduous azaleas are tetraploids.

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Lilac Lights',
Diploid 'Orchid Lights',
Diploid 'Rosy Lights',
Triploid 'Spicy Lights',
Triploid 'White Lights',
Tetraploid Rhododendron atlanticum,
Tetraploid Rhododendron calendulaceum,
Tetraploid Rhododendron luteum,
Tetraploid 'Apricot Surprise',
Tetraploid 'Candy Lights',
Tetraploid 'Golden Lights',
Tetraploid 'Lemon Lights',
Tetraploid 'Mandarin Lights',
Tetraploid 'Northern Hi-Lights',
Tetraploid 'Tri-Lights'

Source: Kristian Theqvist

John and Sally Perkins