Rhododendron 'Fox's Favorite' has been determined to be a triploid 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.
'Fox's Favorite', which is a red, is suspected of being either 'Grace Seabrook' or 'Taurus'. The ploidy results support this position.
Summary of Ploidy Levels
Diploid 'The Honorable Jean Marie de Montague',
Triploid 'Fox's Favorite',
Triploid 'Grace Seabrook',
Source: Bob Fox
John and Sally Perkins