Rhododendron luteum Orange form has been determined to be a tetraploid using flow cytometry by
Dr. João Loureiro, Dr. Silvia Castro, 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 luteum was also determined to be a tetraploid using flow cytometry by Dr. Thomas Ranney, J.R. Jones, and Nathan Lynch.
Summary of Ploidy Levels
Tetraploid Rhododendron luteum,
Tetraploid Rhododendron luteum 'Golden Comet',
Tetraploid Rhododendron luteum Orange form,
Tetraploid Rhododendron luteum Yellow form
Source: Kristian Theqvist
John and Sally Perkins