Rhododendron 'Marinus Koster', which is a 1937 Koster hybrid documented as R. griffithianum hybrid, has 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.
'Marinus Koster' is one of the oldest known tetraploid large leaf elepidote hybrid.
'Marinus Koster' is a parent of 'Arnold Piper', 'Cotton Candy', 'El Camino', 'Lem's Monarch', 'Point Defiance', and 'Rendezvous'.
Halfdan Lem named several crosses of 'Anna' by 'Marinus Koster'.
Summary of Ploidy Levels
Diploid 'Anna',
Diploid 'Rendezvous',
Triploid 'Cotton Candy',
Triploid 'El Camino',
Tetraploid 'Lem's Monarch',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance',
Suspected Polyploid 'Arnold Piper'
Source: Whitney Nursery
John and Sally Perkins
