Rhododendron 'J.G. Millais', which is a 1915 Waterer hybrid documented as 'Ascot Brilliant' x 'Pink Pearl', has been determined to be a diploid 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 'J.G. Millais' has as ancestors 'Broughtonii' and 'Pink Pearl' which are both triploids.
Summary of Ploidy Levels
Diploid 'J.G. Millais',
Triploid 'Broughtonii',
Triploid 'Pink Pearl'
Source: Van Veen Nursery
John and Sally Perkins
