'Aamurusko' is a Triploid

Rhododendron 'Aamurusko', which is a Finnish Ghent hybrid, has been determined to be a triploid 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.

Summary of Ploidy Levels

Diploid 'Miniatum Floribundum',
Triploid 'Aida',
Triploid 'Aamurusko',
Triploid 'Bronze Unique',
Triploid 'Croceum Tricolor',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Freya',
Triploid 'Gloria Mundi',
Triploid 'Il Tasso',
Triploid 'Josephine Klinger',
Triploid 'Phebe',
Triploid 'Phidias',
Triploid 'Pontica Album',
Triploid 'Van Houttei Flore Pleno',
Triploid 'Velasquez',
Triploid/Tetraploid 'Praxitèle',
Tetraploid 'Admiraal De Ruyter',
Tetraploid 'Altaclerensis',
Tetraploid 'Ariel',
Tetraploid 'Beaté Céleste',
Tetraploid 'Bijou des Amateurs',
Tetraploid 'Bouquet de Flore',
Tetraploid 'Cardinal,
Tetraploid 'Comte de Flandre',
Tetraploid 'Corneille',
Tetraploid 'Directeur Charles Baumann',
Tetraploid 'Durante Alle',
Tetraploid 'Electum',
Tetraploid 'Eugénie',
Tetraploid 'Fénelon',
Tetraploid 'Flameola Incarnata',
Tetraploid 'Héroine Plena,
Tetraploid 'Heureuse Surprise',
Tetraploid 'Hollandia',
Tetraploid 'Hora',
Tetraploid 'Ignacea',
Tetraploid 'Igneum Novum',
Tetraploid 'Il Tasso',
Tetraploid 'Jenny Lind',
Tetraploid 'Juliana Nova',
Tetraploid 'Julius Caesar',
Tetraploid 'Leibuir',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Marie Verschaffelt',
Tetraploid 'Minerva',
Tetraploid 'Nancy Waterer',
Tetraploid 'Oscar I',
Tetraploid 'Perfecta',
Tetraploid 'Princesse d' Orange',
Tetraploid 'Raphael de Smet'

Source: Kristian Theqvist

John and Sally Perkins

'Frosthexe' is a Triploid

Rhododendron 'Frosthexe', which is a Reich hybrid documented as Rhododendron anthopogon ssp. anthopogon X Rhododendron lapponicum, has been determined to be a triploid 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.

Summary of Ploidy Levels

Diploid Rhododendron dauricum,
Diploid Rhododendron hippophaeoides,
Diploid Rhododendron keiskei,
Diploid Rhododendron lapponicum,
Diploid Rhododendron micranthum,
Diploid Rhododendron minus,
Diploid Rhododendron mucronulatum,
Diploid Rhododendron racemosum,
Triploid 'Angel Powder',
Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Evening Sky',
Triploid 'Frosthexe',
Triploid 'Kehr's White Ruffles',
Triploid 'Purple Gem',
Triploid 'Ramapo',
Triploid 'Ramolet',
Triploid 'Veesprite',
Tetraploid Rhododendron augustinii,
Tetraploid Rhododendron minus var. minus 'Epoch'

Source: Kristian Theqvist

John and Sally Perkins

Rhododendron columbianum is a Diploid

Rhododendron columbianum has been determined to be a diploid 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 columbianum is often documented as being a hybrid between Rhododendron groenlandicum and Rhododendron neoglandulosum. Since Rhododendron groenlandicum and Rhododendron neoglandulosum are tetraploid, Rhododendron columbianum, being diploid, is most likely a separate species.

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Kristian Theqvist
Source: Hans Eiberg
Source: Robert MacIntyre

John and Sally Perkins

Rhododendron tolmachevii is a Tetraploid

Rhododendron tolmachevii 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

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Kristian Theqvist
Source: John and Sally Perkins

John and Sally Perkins

Rhododendron neoglandulosum is a Tetraploid

Rhododendron neoglandulosum 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

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Kristian Theqvist

John and Sally Perkins

Rhododendron hypoleucum is a Tetraploid

Rhododendron hypoleucum 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

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Kristian Theqvist

John and Sally Perkins

Rhododendron diversipilosum is a Tetraploid

Rhododendron diversipilosum 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 diversipilosum was formerly classified as Ledum palustre var. diversipilosum.

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Kristian Theqvist

John and Sally Perkins

Rhododendron tomentosum Turku Archipelago is a Tetraploid

Rhododendron tomentosum Turku Archipelago 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 tomentosum was formerly classified as Ledum.

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Kristian Theqvist

John and Sally Perkins

Rhododendron luteum Yellow form is a Tetraploid

Rhododendron luteum Yellow 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

Rhododendron luteum Orange form is a Tetraploid

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

'Django' is a Triploid

Rhododendron 'Django', which is a Hachmann hybrid documented as 'Abendglut' x Rhododendron brachycarpum ssp tigerstedtii, has been determined to be a triploid 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.

Summary of Ploidy Levels

Triploid 'Django'

Source: Kristian Theqvist

John and Sally Perkins

'Lilac Lights' is a Diploid

Rhododendron 'Lilac Lights', which is in the Northern Lights group from the University of Minnesota documented as Rhododendron canadense X Rhododendron molle hybrid, has been determined to be a diploid 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.

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Frank Abbott',
Diploid 'Jane Abbott',
Diploid 'Lilac Lights',
Diploid 'Orchid Lights',
Diploid 'Rosy Lights',
Triploid 'Spicy Lights',
Triploid 'White Lights',
Tetraploid Rhododendron atlanticum,
Tetraploid Rhododendron calendulaceum,
Tetraploid Rhododendron luteum,
Tetraploid 'Apricot Surprise',
Tetraploid 'Candy Lights',
Tetraploid 'Golden Lights',
Tetraploid 'Lemon Lights',
Tetraploid 'Mandarin Lights',
Tetraploid 'Northern Hi-Lights',
Tetraploid 'Tri-Lights'

Source: Kristian Theqvist

John and Sally Perkins

'Rosy Lights' is a Diploid

Rhododendron 'Rosy Lights', which is in the Northern Lights group from the University of Minnesota documented as Rhododendron prinophyllum X Rhododendron molle, has been determined to be a diploid 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.

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Frank Abbott',
Diploid 'Jane Abbott',
Diploid 'Lilac Lights',
Diploid 'Orchid Lights',
Diploid 'Rosy Lights',
Triploid 'Spicy Lights',
Triploid 'White Lights',
Tetraploid Rhododendron atlanticum,
Tetraploid Rhododendron calendulaceum,
Tetraploid Rhododendron luteum,
Tetraploid 'Apricot Surprise',
Tetraploid 'Candy Lights',
Tetraploid 'Golden Lights',
Tetraploid 'Lemon Lights',
Tetraploid 'Mandarin Lights',
Tetraploid 'Northern Hi-Lights',
Tetraploid 'Tri-Lights'

Source: Kristian Theqvist

John and Sally Perkins

'Spicy Lights' is a Triploid

Rhododendron 'Spicy Lights', which is in the Northern Lights group from the University of Minnesota documented as Rhododendron prinophyllum as the seed parent, has been determined to be a triploid 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 'Spicy Lights' appears to be sterile.

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Lilac Lights',
Diploid 'Orchid Lights',
Diploid 'Rosy Lights',
Triploid 'Spicy Lights',
Triploid 'White Lights',
Tetraploid Rhododendron atlanticum,
Tetraploid Rhododendron calendulaceum,
Tetraploid Rhododendron luteum,
Tetraploid 'Apricot Surprise',
Tetraploid 'Candy Lights',
Tetraploid 'Golden Lights',
Tetraploid 'Lemon Lights',
Tetraploid 'Mandarin Lights',
Tetraploid 'Northern Hi-Lights',
Tetraploid 'Tri-Lights'

Source: Kristian Theqvist

John and Sally Perkins

'White Lights' is a Triploid

Rhododendron 'White Lights', which is in the Northern Lights group from the University of Minnesota documented as Rhododendron prinophyllum X white Exbury, has been determined to be a triploid 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 'White Lights' appears to be sterile.

Most Exbury deciduous azaleas are tetraploids.

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Lilac Lights',
Diploid 'Orchid Lights',
Diploid 'Rosy Lights',
Triploid 'Spicy Lights',
Triploid 'White Lights',
Tetraploid Rhododendron atlanticum,
Tetraploid Rhododendron calendulaceum,
Tetraploid Rhododendron luteum,
Tetraploid 'Apricot Surprise',
Tetraploid 'Candy Lights',
Tetraploid 'Golden Lights',
Tetraploid 'Lemon Lights',
Tetraploid 'Mandarin Lights',
Tetraploid 'Northern Hi-Lights',
Tetraploid 'Tri-Lights'

Source: Kristian Theqvist

John and Sally Perkins

Rhododendron luteum is a Tetraploid

Rhododendron luteum 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.

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: Arnold Arboretum
Source: John and Sally Perkins
Source: Kristian Theqvist

John and Sally Perkins

'Pearce's American Beauty' is a Triploid

Rhododendron 'Pearce's American Beauty', which is a Pearce hybrid documented as 'Mrs Charles S Sargent' x 'Doctor H.C. Dresselhuys', has been determined to be a triploid using flow cytometry by

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.

Rhododendron 'Pearce's American Beauty' may be fertile since the ARS Seed Exchange List contains seed from the cross 'Tooney Bird' X 'Pearce's American Beauty'

Summary of Ploidy Levels

Triploid 'Pearce's American Beauty'

Source: RareFind Nursery
Source: Kristian Theqvist

John and Sally Perkins

Rhododendron groenlandicum is a Tetraploid

Rhododendron groenlandicum has been determined to be a tetraploid using flow cytometry by

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.

Rhododendron groenlandicum was formerly classified as Ledum groenlandicum.

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: Bartlett Arboretum
Source: Saco Bog, Maine (John and Sally Perkins)
Source: Kristian Theqvist

John and Sally Perkins

Rhododendron diversipilosum 'Milky Way' is a Tetraploid

Rhododendron diversipilosum 'Milky Way' has been determined to be a tetraploid using flow cytometry by

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.

Rhododendron diversipilosum was formerly classified as Ledum palustre var. diversipilosum.

Summary of Ploidy Levels

Diploid Rhododendron columbianum,
Diploid Rhododendron subarticum,
Diploid Rhododendron subulatum China,
Tetraploid Rhododendron diversipilosum,
Tetraploid Rhododendron diversipilosum 'Milky Way',
Tetraploid Rhododendron groenlandicum,
Tetraploid Rhododendron groenlandicum Saco Bog, Maine,
Tetraploid Rhododendron hypoleucum,
Tetraploid Rhododendron neoglandulosum,
Tetraploid Rhododendron tolmachevii,
Tetraploid Rhododendron tomentosum Turku Archipelago

Source: RareFind Nursery
Source: Kristian Theqvist

John and Sally Perkins

Rhododendron canadense is a Diploid

Rhododendron canadense has been determined to be a diploid 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.

Rhododendron canadense was also determined to be a diploid using flow cytometry by Dr. Thomas Ranney, J.R. Jones, and Nathan Lynch. The Ranney research involved several samples from diverse wild populations including samples from Salem, New Hampshire.

Read Ploidy Level of Rhododendron canadense

Summary of Ploidy Levels

Diploid Rhododendron canadense,
Diploid Rhododendron canadense var. album
Diploid Rhododendron canadense 'Osku's Showy'

Source: Arnold Arboretum Accession Number: 199-2006-C
Source: Bruce Clyburn
Source: John and Sally Perkins
Source: Kristian Theqvist

John and Sally Perkins