Rhododendron 'Bronze Unique', which is a 1849 Louis Verschaffelt Ghent hybrid, has been determined to be a triploid 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.
The Ghents are documented as having been produced from crossing diploid and tetraploid deciduous azalea species. This result appears to support that documentation.
The plant of Rhododendron 'Bronze Unique' tested does not agree in some characteristics with earlier descriptions of this cultivar. Moreover this plant tested at the high end of the range for triploids.
Summary of Ploidy Levels
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger'
Source: Arnold Arboretum Accession Number: 19403
John and Sally Perkins
