Two seedlings of Rhododendron 'Horizon Lakeside' x 'Point Defiance', which were raised by Ned Brockenbrough, have 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.
Summary of Ploidy Levels
Diploid 'Horizon Lakeside'
Tetraploid 'Point Defiance'
Tetraploid 2 Seedlings of 'Horizon Lakeside' x 'Point Defiance'
Source: Ned Brockenbrough
John and Sally Perkins
