Rhododendron 'Julius Caesar', which is a prior to 1872 Ghent hybrid, 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.
Rhododendron 'Julius Caesar' is very fertile.
To date, all Ghent deciduous azaleas have tested as triploid or tetraploid.
Summary of Ploidy Levels
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid 'Comte de Flandre',
Tetraploid 'Ignacea',
Tetraploid 'Julius Caesar',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Nancy Waterer',
Tetraploid 'Raphael de Smet'
Source: Arnold Arboretum Accession Number: 17109
John and Sally Perkins
