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
