'Lady De Rothchild' is a Diploid

Rhododendron 'Lady De Rothchild', which is a 1925 Waterer hybrid documented as Rhododendron griffithianum x 'Sappho' has been determined to be a diploid 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.

Summary of Ploidy Levels

Diploid 'Lady De Rothchild'

Source: Whitney Nursery

John and Sally Perkins

'Julia Caroline' is a Triploid

Rhododendron 'Julia Caroline', which is a Ned Brockenbrough hybrid documented as 'Horizon Lakeside' x 'Point Defiance', 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.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Horizon Lakeside',
Diploid 'Nancy Evans',
Diploid 'Norman Gill'
Diploid 'The Honourable Jean Marie de Montague',
Triploid 'Julia Caroline',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance'

Source: Whitney Nursery

John and Sally Perkins

'Alice' is a Diploid

Rhododendron 'Alice', which is a 1910 Waterer hybrid documented as Rhododendron griffithianum hybrid has been determined to be a diploid 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.

Summary of Ploidy Levels

Diploid 'Alice'

Source: Whitney Nursery

John and Sally Perkins

'Lady Bligh' is a Diploid

Rhododendron 'Lady Bligh', which is a 1958 C.B. van Nes hybrid documented as Rhododendron griffithianum hybrid has been determined to be a diploid 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.

Summary of Ploidy Levels

Diploid 'Lady Bligh'

Source: Whitney Nursery

John and Sally Perkins

'Daviesii' is a Fertile Triploid

Rhododendron 'Daviesii', which is a 1840 Isaac Davies hybrid often documented as Rhododendron viscosum X Rhododendron molle, 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.

Rhododendron 'Daviesii' is documented to be the seed parent of 'Moorgold', which is a Schmalscheidt hybrid. John Migas has indicated that 'Daviesii' sets viable seed.

Davies' notes indicate that 'Daviesii' was produced using "A. sinesis crossed a hardy white azaleas."

Rhododendron 'Viscosepalum', which is often documented to be Rhododendron molle X Rhododendron viscosum, has been determined to be a tetraploid.

The flow cytometry ploidy results for 'Daviesii' and 'Viscosepalum' indicate the pollen parent may have been the tetraploid Rhododendron atlanticum rather than the diploid Rhododendron viscosum. The normal bloom times for Rhododendron molle and Rhododendron atlanticum overlay whereas this is not the case for Rhododendron molle and Rhododendron viscosum. Rhododendron viscosum and Rhododendron atlanticum are known to colocate in the wild.

'Viscosepalum' and 'Daviesii' are sometimes confused in commercial settings.

Rhododendron 'Daviesii' was also determined to be a triploid using flow cytometry by Tom Eeckhaut.

Plants labeled Rhododendron 'Daviesii' have also tested as tetraploid and pentaploid.

Summary of Ploidy Levels

Diploid Rhododendron molle,
Diploid Rhododendron viscosum,
Triploid 'Graf von Meran',
Triploid 'Daviesii',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid Rhododendron atlanticum,
Tetraploid 'Viscosepalum'

Source: Greer Gardens
Source: Whitney Nursery
Source: Azaleatuin

John and Sally Perkins

'Summer Wind' is a Diploid

Rhododendron 'Summer Wind', which is a Jim Barlup hybrid documented as 'Golden Gala' x 'Summer Peach', 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 'Summer Wind' has as ancestors 'Broughtonii', 'Pink Pearl', 'Gomer Waterer', 'Phyllis Korn', and 'Summer Peach'.

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Madame Carvalho',
Diploid 'Mrs. Lindsay Smith',
Diploid 'Summer Peach',
Diploid 'Summer Wind',
Triploid 'Broughtonii',
Triploid 'Gomer Waterer',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl'

Source: Whitney Nursery

John and Sally Perkins

'Mindy’s Love' is a Diploid

Rhododendron 'Mindy’s Love', which is a Jim Barlup hybrid documented as 'Nancy Evans' x 'Lionel's Triumph', 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.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Hotei',
Diploid 'Lem's Cameo',
Diploid 'Mindy’s Love',
Diploid 'Nancy Evans',
Diploid 'Norman Gill',
Diploid 'The Honorable Jean Marie de Montague'

Source: Whitney Nursery

John and Sally Perkins

'Mother of Pearl' is a Diploid

Rhododendron 'Mother of Pearl', which is documented as a sport of 'Pink Pearl', 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.

Summary of Ploidy Levels

Diploid 'Mother of Pearl',
Triploid 'Broughtonii',
Triploid ''Ebony Pearl',
Triploid 'Topsvoort Pearl',
Triploid 'Pink Pearl'

Source: Whitney Nursery

John and Sally Perkins

'Legend' is a Tetraploid

Rhododendron 'Legend', which is a Jim Barlup hybrid documented as 'Point Defiance' x 'Lem's Monarch', 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 'Legend' has as ancestors 'Anna', 'Norman Gill', 'The Honourable Jean Marie de Montague', 'Marinus Koster', 'Point Defiance', and 'Lem's Monarch'.

In the case of the tetraploid 'Legend', a tetraploid crossed with a tetraploid produced a tetraploid indicating that normal reduced meiosis most likely occurred for both parents. In other words, 'Legend' having 52 chromosomes received 26 chromosomes from the tetraploid 'Point Defiance' and 26 chromosomes from the tetraploid 'Lem's Monarch'.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Norman Gill',
Diploid 'The Honourable Jean Marie de Montague',
Tetraploid 'Legend',
Tetraploid 'Lem's Monarch',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance'

Source: Whitney Nursery

John and Sally Perkins

'Super Dog' is a Triploid

Rhododendron 'Super Dog', which is a Dan Bones hybrid documented as 'Confusion' x 'Pink Walloper', 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.

In the case of the triploid 'Super Dog', a suspected diploid crossed with a tetraploid produced a triploid indicating that normal reduced meiosis most likely occurred for the tetraploid parent. In other words, 'Super Dog' having 39 chromosomes most likely received 13 chromosomes from 'Confusion' and 26 chromosomes from the tetraploid 'Trude Webster'.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Norman Gill',
Diploid 'The Honourable Jean Marie de Montague',
Triploid 'Super Dog',
Tetraploid 'Marinus Koster',
Tetraploid 'Pink Walloper'

Source: Whitney Nursery

John and Sally Perkins

'Gorgeous George' is a Tetraploid

Rhododendron 'Gorgeous George', which is a Sanders hybrid documented as 'Point Defiance' x 'Trude Webster', 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 'Gorgeous George' has as ancestors 'Anna', 'Norman Gill', 'The Honourable Jean Marie de Montague', 'Broughtonii', 'Cynthia', 'Pink Pearl', 'Marinus Koster', 'Point Defiance', 'Countess of Derby', and 'Trude Webster'.

In the case of the tetraploid 'Gorgeous George', a tetraploid crossed with a tetraploid produced a tetraploid indicating that normal reduced meiosis most likely occurred for both parents. In other words, 'Gorgeous George' having 52 chromosomes received 26 chromosomes from the tetraploid 'Point Defiance' and 26 chromosomes from the tetraploid 'Trude Webster'.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Norman Gill',
Diploid 'The Honourable Jean Marie de Montague',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Tetraploid 'Countess of Derby',
Tetraploid 'Doreen Gale',
Tetraploid 'Gorgeous George',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance',
Tetraploid 'Trude Webster'

Source: Whitney Nursery

John and Sally Perkins

'Antoon van Welie' is a Tetraploid

Rhododendron 'Antoon van Welie', which is a pre 1930 Endtz hybrid documented as 'Pink Pearl' x R. catawbiense, 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 'Antoon van Welie' has 'Broughtonii' and 'Pink Pearl' as a ancestors and 'Lydia' and 'Grand Slam' as descendants.

In the case of the tetraploid 'Antoon van Welie', a triploid crossed with a likely diploid produced a tetraploid indicating that unreduced meiosis occurred for either the triploid 'Pink Pearl' or the likely diploid R. catawbiense. In other words, 'Antoon van Welie' having 52 chromosomes either 1) received all 39 of 'Pink Pearl' chromosomes plus 13 from R. catawbiense or 2) received 26 from 'Pink Pearl' plus all 26 of R. catawbiense chromosomes.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Lydia',
Triploid 'Pink Pearl',
Tetraploid 'Antoon van Welie',
Tetraploid 'Grand Slam',
Tetraploid 'Trude Webster'

Source: Whitney Nursery
Source: Van Veen Nursery

John and Sally Perkins

'Summer Peach' is a Diploid

Rhododendron 'Summer Peach', which is a Jim Barlup hybrid documented as 'Whitney's Late Peach' X 'Phyllis Korn', 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 'Summer Peach' has as ancestors 'Broughtonii', 'Pink Pearl', 'Gomer Waterer', and 'Phyllis Korn' which are all triploids. 'Summer Peach' has as descendants 'Peach Recital' and 'Summer Wind' which are both diploids.

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Madame Carvalho',
Diploid 'Mrs. Lindsay Smith',
Diploid 'Peach Recital',
Diploid 'Summer Peach',
Diploid 'Summer Wind',
Triploid 'Broughtonii',
Triploid 'Gomer Waterer',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl'

Source: Whitney Nursery

John and Sally Perkins

'Graf Zeppelin' is a Diploid

Rhododendron 'Graf Zeppelin', which is a C. B. Van Nes hybrid documented as 'Pink Pearl' x 'Mrs. Charles S. Sargent', 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 'Graf Zeppelin' has as ancestors 'Broughtonii' and 'Pink Pearl' which are both triploids.

Summary of Ploidy Levels

Diploid 'Graf Zeppelin',
Triploid 'Broughtonii',
Triploid 'Pink Pearl'

Source: Van Veen Nursery
Source: Whitney Nursery

John and Sally Perkins

'Voluptuous' is a Diploid

Rhododendron 'Voluptuous', which is a Werner Brack hybrid documented as 'Scintillation' X 'Mary Belle', 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.

Summary of Ploidy Levels

Diploid 'Voluptuous'

Source: Whitney Nursery

John and Sally Perkins

'Cotton Candy' is a Fertile Triploid

Rhododendron 'Cotton Candy', which is a Henny and Wennekamp hybrid documented as 'Loderi Venus' x 'Marinus Koster', 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.

Rhododendron 'Cotton Candy' has been successfully used as both a seed and pollen parent by L. L. Newcomb and M. Stockman.

In the case of the triploid (39 chromosomes) 'Cotton Candy', a diploid crossed with a tetraploid produced a triploid indicating normal meiosis occurred where the diploid 'Loderi Venus' contributed a 1x gamete (13 chromosomes) and the tetraploid 'Marinus Koster' contributed a 2x gamete (26 chromosomes).

Summary of Ploidy Levels

Diploid 'Loderi Venus',
Triploid 'Cotton Candy',
Tetraploid 'Marinus Koster'

Source: Whitney Nursery

John and Sally Perkins

'Marinus Koster' is a Tetraploid

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

'Beauty of Littleworth' is a Triploid

Rhododendron 'Beauty of Littleworth', which is a 1884 James Henry Mangles hybrid documented as R. griffithianum x R. campanulatum ssp. campanulatum, 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.

Summary of Triploids from the 19th century

'Broughtonii' 1840,
'Cynthia' 1856,
'Beauty of Littleworth' 1884,
'Pink Pearl' 1892,
'Gomer Waterer' 1900

Source: Whitney Nursery

John and Sally Perkins

'Diane' is a Diploid

Rhododendron 'Diane', which is a Koster hybrid documented as a 'Mrs. Lindsay Smith' hybrid, 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.

'Diane' is the seed parent of 'Phyllis Korn', which is a triploid. 'Gomer Waterer', which is a triploid and has 'Broughtonii' and 'Pink Pearl' as ancestors, is the pollen parent of 'Phyllis Korn'.

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Mrs. Lindsay Smith',
Diploid 'Rothenburg',
Triploid 'Broughtonii',
Triploid 'Gomer Waterer',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl'

Source: Whitney Nursery

John and Sally Perkins

'Cynthia' is a Fertile Triploid

Rhododendron 'Cynthia', which is a 1856 Standish and Noble hybrid documented as R. catawbiense x R. griffithianum, 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.

'Cynthia' is the pollen parent of 'Countess of Derby'. M. Stockman used 'Cynthia' as a seed or pollen parent in several of his crosses.

'Countess of Derby', which has 'Pink Pearl' and 'Cynthia' as parents and 'Broughtonii' as an ancestor, is a cross between 2 fertile triploids.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Tetraploid 'Countess of Derby'

Source: Whitney Nursery

John and Sally Perkins