Three seedlings of Rhododendron "(cumberlandense X lutem) not" have been determined to be a diploid using flow cytometry by
Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, 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.
Ploidy testing indicates that Rhododendron luteum may not be the pollen parent of this hybrid.
Summary of Ploidy Levels
Diploid Rhododendron cumberlandense,
Diploid 3 Seedlings of "(cumberlandense X luteum) not",
Tetraploid Rhododendron luteum
Source: Bruce Clyburn
John and Sally Perkins