In August 2011, 4 newspapers in Portugal published articles on polyploid Rhododendrons based on the flow cytometry results of
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.
Here is a quote translated to English from one of those articles.
"Until now it was assumed that triploid rhododendrons (three equal in their genome copies) were sterile. There are triploid rhododendrons that are fertile and therefore able to produce viable offspring."