Rhododendron 'Toucan', which is a Waterer hybrid documented as a Mollis 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 'Toucan' is very fertile.
Rhododendron molle is a diploid species.
Summary of Ploidy Levels
Diploid Rhododendron molle,
Tetraploid 'Toucan'
Source: Arnold Arboretum Accession Number: 189-72
John and Sally Perkins
