Rhododendron 'Countess of Athlone', which is a van Nes hybrid documented as 'Geoffroy Millais' x R. catawbiense 'Catawbiense Grandiflorum', 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.
Summary of Ploidy Levels
Diploid 'Countess of Athlone'
Source Marc Colombel
John and Sally Perkins
