'Hallelujah' is a Triploid

Rhododendron 'Hallelujah', which is a Harold Greer hybrid documented as 'The Honourable Jean Marie de Montague' x 'Kimberly', 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 'The Honourable Jean Marie de Montague',
Triploid 'Hallelujah'

Source: Greer Gardens
Source: Bob Fox

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

'Halopeanum' is a Diploid

Rhododendron 'Halopeanum', which is a 1896 Halopé hybrid documented as Rhododendron griffithianum x Rhododendron maximum, 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 'Halopeanum' syn 'White Pearl'

Source: Greer Gardens

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

'Bouquet de Flore' is a Tetraploid

Rhododendron 'Bouquet de Flore', which is a 1864 Verschaffelt Ghent hybrid, 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.

Summary of Ploidy Levels

Triploid 'Aida',
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid 'Admiraal De Ruyter',
Tetraploid 'Altaclerensis',
Tetraploid 'Ariel',
Tetraploid 'Beaté Céleste',
Tetraploid 'Bijou des Amateurs',
Tetraploid' Bouquet de Flore',
Tetraploid 'Comte de Flandre',
Tetraploid 'Heureuse Surprise',
Tetraploid 'Ignacea',
Tetraploid 'Julius Caesar',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Nancy Waterer',
Tetraploid 'Oscar I',
Tetraploid 'Raphael de Smet'

Source: Azaleatuin

John and Sally Perkins

(Rhododendron yakushimanum x 'Taurus') is a Triploid

(Rhododendron yakushimanum x 'Taurus'), which is a Jack Rosenthal hybrid, 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

Triploid Rhododendron yakushimanum x 'Taurus',
Triploid 'Taurus'

Source: Werner Brack

John and Sally Perkins

Reminder: Chapter Field Trip to Cochato Nursery @ Sun Jun 26 10:30am - 1pm (John Perkins)

more details » Chapter Field Trip to Cochato Nursery Chapter Field Trip to Cochato Nursery 373 North Franklin St., Holbrook MAHolbrook When Sun Jun 26 10:30am – 1pm Eastern Time Where 373 North Franklin St., Holbrook MAHolbrook (map) Calendar John Perkins Who • John.A.Perkins@gmail.com - creator

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Reminder: P4M Workday: Planeview Nursery - Stick @ Sat Jun 25 10am - 12pm (John Perkins)

more details » P4M Workday: Planeview Nursery - Stick Stick Cuttings When Sat Jun 25 10am – 12pm Eastern Time Where 770 Wapping Road, Portsmouth, RI (map) Calendar John Perkins Who • John.A.Perkins@gmail.com - creator

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'Ariel' is a Tetraploid

Rhododendron 'Ariel', which is a 1936 H. White Ghent hybrid documented as a 'Standishii' hybrid, 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.

Summary of Ploidy Levels

Triploid 'Aida',
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid 'Admiraal De Ruyter',
Tetraploid 'Altaclerensis',
Tetraploid 'Ariel',
Tetraploid 'Beaté Céleste',
Tetraploid 'Bijou des Amateurs',
Tetraploid' Bouquet de Flore',
Tetraploid 'Comte de Flandre',
Tetraploid 'Heureuse Surprise',
Tetraploid 'Ignacea',
Tetraploid 'Julius Caesar',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Nancy Waterer',
Tetraploid 'Oscar I',
Tetraploid 'Raphael de Smet'

Source: Azaleatuin

John and Sally Perkins

'Altaclerensis' is a Tetraploid

Rhododendron 'Altaclerensis', which is a 1862 Lee exhibited F.C.C Ghent hybrid documented as Rhododendron molle x unknown Ghent hybrid, 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.

The Rhododendron 'Altaclerensis' tested here is the yellow flowered one which is different from the 1842 'Altaclarense' introduced by Lord Carvanon in Highclere.

History of the earlier 'Altaclarense':

Azalea altaclarensis - Gowen apud Lindley in Bot. Reg. XXVIII. t. 27 (1842),
not Rhododendron altaclarense Lindl.

This handsome hybrid was raised at Highclere by J. R. Gowen, who states
that "it was produced by fertilizing the flowers of Azalea sinensis with the pollen
of the late flowering variety of Azalea viscosa, called by nurserymen A. rubescens
major." The flowers are large white, slightly bordered pink, with a faint yellow
tinge at the base of the lobes, and with the upper lobe distinctly dotted yellow
and the tube pinkish outside. The gradually dilated tube and the yellow tinge
and the spotted upper lobe indicate the influence of R. sinense and the white
color and hirsute tube of the corolla and the delicious fragrance the influence of
R. viscosum.

Summary of Ploidy Levels

Diploid Rhododendron molle,
Triploid 'Aida',
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid 'Admiraal De Ruyter',
Tetraploid 'Altaclerensis',
Tetraploid 'Ariel',
Tetraploid 'Beaté Céleste',
Tetraploid 'Bijou des Amateurs',
Tetraploid' Bouquet de Flore',
Tetraploid 'Comte de Flandre',
Tetraploid 'Heureuse Surprise',
Tetraploid 'Ignacea',
Tetraploid 'Julius Caesar',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Nancy Waterer',
Tetraploid 'Oscar I',
Tetraploid 'Raphael de Smet'

Source: Azaleatuin

John and Sally Perkins

'Aida' is a Triploid

Rhododendron 'Aida', which is a 1888 L. de Smet Rustica hybrid, 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.

Rustica hybrids are a mixture of double flowered Ghents hybrids and the Mollis hybrids. The Mollis hybrids contain the diploid species Rhododendron molle. To date all Ghent hybrids (except one)including the doubles have tested as triploid or tetraploid.

Summary of Ploidy Levels

Diploid Rhododendron molle,
Triploid 'Aida',
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid 'Admiraal De Ruyter',
Tetraploid 'Altaclerensis',
Tetraploid 'Ariel',
Tetraploid 'Beaté Céleste',
Tetraploid 'Bijou des Amateurs',
Tetraploid' Bouquet de Flore',
Tetraploid 'Comte de Flandre',
Tetraploid 'Heureuse Surprise',
Tetraploid 'Ignacea',
Tetraploid 'Julius Caesar',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Nancy Waterer',
Tetraploid 'Oscar I',
Tetraploid 'Raphael de Smet'

Source: Azaleatuin

John and Sally Perkins

How to Plant a Rhododendron

The links below are videos on how to plant a Rhododendron:

How to Plant by RareFind Nursery in Jackson NJ

How to Plant by Nettle Creek Nursery

'Admiraal De Ruyter' is a Tetraploid

Rhododendron 'Admiraal De Ruyter', which is a 1849 Van Houtte Ghent hybrid, 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.

Summary of Ploidy Levels

Triploid 'Aida',
Triploid 'Bronze Unique',
Triploid 'Daviesii',
Triploid 'Deep Rose',
Triploid 'Gloria Mundi',
Triploid 'Josephine Klinger',
Tetraploid 'Admiraal De Ruyter',
Tetraploid 'Altaclerensis',
Tetraploid 'Ariel',
Tetraploid 'Beaté Céleste',
Tetraploid 'Bijou des Amateurs',
Tetraploid' Bouquet de Flore',
Tetraploid 'Comte de Flandre',
Tetraploid 'Heureuse Surprise',
Tetraploid 'Ignacea',
Tetraploid 'Julius Caesar',
Tetraploid 'Lelia',
Tetraploid 'Madame Gustave Guillemot',
Tetraploid 'Nancy Waterer',
Tetraploid 'Oscar I',
Tetraploid 'Raphael de Smet'

Source: Azaleatuin

John and Sally Perkins

"Jane Abbott" is a Diploid

2 Different "Jane Abbott"s (Frank Abbott) [2x]
Next to graves of Frank and Jane Abbott
S and J Perkins

Two different Rhododendron "Jane Abbott" types, which are a Frank Abbott hybrids documented as Rhododendron prinophyllum x 'Miss Louisa Hunnewell', have been determined to be diploids 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.

Frank Abbott started crossing Rhododendron prinophyllum and 'Miss Louisa Hunnewell' in the 1930's giving the best results of this cross the name Rhododendron "Jane Abbott" after his daughter.

'Miss Louisa Hunnewell' is a Rhododendron molle resulting from the cross of the Japanese and Chinese form of the species. At one time, 'Miss Louisa Hunnewell' was considered to be the best Rhododendron molle in North America.

Rhododendron "Jane Abbott" is rarely seed or pollen fertile. This lack of fertility may indicate that Rhododendron molle is not closely related to Rhododendron prinophyllum. Dr. Benjamin Hall's DNA has placed Rhododendron molle and Rhododendron prinophyllum in different clades and he suggests that Rhododendron molle DNA is closer to the tetraploid clade of deciduous azaleas than the diploid clade of deciduous azaleas.

Rhododendron "Jane Abbott" is also difficult to root from cuttings.

The two "Jane Abbott" tested are the 2 different "pinks" planted at the Saxton River cemetery next to the gravestones of Frank Abbott and his daughter Jane.

Read Frank Abbott's Village of Azaleas"

Summary of Ploidy Levels

Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Frank Abbott',
Diploid Two Different "Jane Abbott" types

Source: John Abbott

John and Sally Perkins

Reminder: P4M Workday: Planeview Nursery - Stick @ Sat Jun 25 10am - 12pm (John Perkins)

more details » P4M Workday: Planeview Nursery - Stick Stick Cuttings When Sat Jun 25 10am – 12pm Eastern Time Where 770 Wapping Road, Portsmouth, RI (map) Calendar John Perkins Who • John.A.Perkins@gmail.com - creator

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Mariana Oliveira e Castro: 2011 Deland Award

We are very pleased to post the following from a letter Mariana Castro received from Dr. Ned Friedman, Director of the Arnold Arboretum:

Dear Mariana,

We are delighted to notify you that you have been selected as a 2011 Deland Award recipient. Your use of the Arboretum collections was of paramount importance in this decision and we look forward to hearing about your research.

...

I want to welcome you to the Arboretum.

Sincerely,
Ned Friedman
Arnold Professor of Organismic and Evolutionary Biology
Director of the Arnold Arboretum

John and Sally Perkins

'Frank Abbott' is a Diploid

Rhododendron 'Frank Abbott', which is a Ed Mezitt hybrid documented as Rhododendron molle hybrid x Rhododendron prinophyllum, 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.

Frank Abbott started crossing Rhododendron prinophyllum and Rhododendron molle in the 1930's giving the best results of this cross the name Rhododendron 'Jane Abbott' after his daughter. When Ed Mezitt redid the cross thirty years later, Ed named one of his best results from the cross Rhododendron 'Frank Abbott'.

Rhododendron 'Frank Abbott' is rarely seed or pollen fertile. This lack of fertility may indicate that Rhododendron molle is not closely related to Rhododendron prinophyllum. Dr. Benjamin Hall's DNA has placed Rhododendron molle and Rhododendron prinophyllum in different clades and he suggests that Rhododendron molle DNA is closer to the tetraploid clade of deciduous azaleas than the diploid clade of deciduous azaleas.

Read Frank Abbott's Village of Azaleas"

Summary of Ploidy Levels

Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Frank Abbott',
Diploid "Jane Abbott" types

Source: John and Sally Perkins

John and Sally Perkins

'H. H. Hume' is a Diploid

Rhododendron 'H. H. Hume', which is documented to be a Beltsville azalea, 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 'H. H. Hume',
Diploid 'Snow'

Source: Mike Creel

John and Sally Perkins

'Kurume Snow' is a Diploid

Rhododendron 'Kurume Snow', which is documented to be a Kurume azalea, 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.

Rhododendron 'Snow' tests at the lowest most end of the range for diploid Rhododendrons which may indicate that evergreen azaleas have a smaller genome size than most other Rhododendrons.

Summary of Ploidy Levels

Diploid 'H. H. Hume',
Diploid 'Kurume Snow'

Source: Mike Creel

John and Sally Perkins

'Harrison's Red' is a Triploid

Rhododendron 'Harrison's Red', which is a documented as Rhododendron austrinum, 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.

The ploidy results suggests that 'Harrison's Red' is a Rhododendron austrinum hybrid rather than a color form of the straight species.

Rhododendron Species Foundation lists 'Harrison's Red' under Rhododendron austrinum as follows:

1993/002 'Harrison's Red' A floriferous and easily grown deciduous azalea with slightly fragrant flowers in mid-spring. The flower color on this selection is listed as "rosy-red" but I have not recorded it in flower. Very heat tolerant, sun or shade. (-10\R1\6)

Summary of Ploidy Levels

Triploid 'Evening Sun',
Triploid 'Harrison's Red',
Tetraploid Rhododendron austrinum

Source: Woodlanders Nursery

John and Sally Perkins

Rhododendron catawbiense is a Diploid

Rhododendron catawbiense 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 Rhododendron catawbiense,
Diploid Rhododendron maximum

Source: Connecticut College Arboretum

John and Sally Perkins

'Margaret Abbott' is a Tetraploid

'Margaret Abbott' (Frank Abbott) [4x]
Rhododendron prinophyllum [2x] X Rhododendron calendulaceum [4x]
Spring 2009 Saxtons River, VT
S and J Perkins

Rhododendron 'Margaret Abbott', which is a Frank Abbott hybrid documented as Rhododendron prinophyllum X Rhododendron calendulaceum, 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 'Margaret Abbott' was named by Frank to honor his wife. Frank was amazed he crossed a pink with a yellow to produce this lone fragrant ruffled white flower with a yellow flare. See A Love Affair With A Flower by Marge Runnion. See Frank Abbott's Village of Azaleas by John and Sally Perkins.

Notice in the image above on the flower facing forward, 'Margaret Abbott' has, at the end of the stamens, tagged anthers, such anthers rarely appear on a deciduous azalea. 'Margaret Abbott' is known to be partially seed fertile but does not appear to have viable pollen.

Notice, also, for 'Margaret Abbott' that the diploid is the seed parent and the tetraploid is the pollen parent. For deciduous azaleas, diploids usually accept pollen from tetraploids but tetraploids usually reject pollen from diploids. See Rules of Engagement by John and Sally Perkins.

In the case of the tetraploid 'Margaret Abbott', a diploid crossed with a tetraploid produced a tetraploid indicating that unreduced meiosis may have occurred for the diploid seed parent. In other words, 'Margaret Abbott' having 52 chromosomes received something on the order of 26 chromosomes from the diploid Rhododendron prinophyllum and 26 chromosomes from the tetraploid Rhododendron calendulaceum. See Unreduced Meiosis. See Ploidy of Deciduous Azaleas Species.

In every other case we have tested where a diploid deciduous azalea is crossed with a tetraploid deciduous azalea, the resulting offspring have been triploids having 39 chromosomes receiving 13 chromosomes from the diploid seed parent and 26 chromosomes from the tetraploid pollen parent. See 2X4 for Deciduous Azaleas. See Normal Meiosis.

Natural interactions of diploid deciduous azalea species and tetraploid diploid deciduous azalea species do occur in places such as Audra State Park. Plants that appear to be interploidy hybrids have tested as triploid and tetraploid. The ploidy results for 'Margaret Abbott' indicated that unreduced gametes of the diploid seed parent may be one of the mechanism causing tetraploids to be produced by diploid X tetraploid interaction. See Audra State Park: Ploidy Haven. See Rhododendron prinophyllum by Elizabeth Carlhian. See Rhododendron arborescens by Susan Clark. See Rhododendron calendulaceum by Joe Bruso.

The hybridizers of the Ghents, including some done by Ed Mezitt, the Rusticas, and the Northen Lights series crossed diploid and tetraploid deciduous azaleas. See Ghent. See Rustica. See Mezitt.

For large leaf elepidote hybrid Rhododendrons we have discovered several instances where a diploid X tetraploid results in tetraploids as well as triploids and diploids. For instance, Rhododendron 'Horizon Monarch', which is a Ned Brockenbrough hybrid documented as 'Nancy Evans' x 'Point Defiance', has been determined to be a tetraploid. 'Nancy Evans' has been determined to be a diploid and 'Point Defiance' has been determined to be a tetraploid. See 2X4 for Large Leaf Elepidotes. See 4X2 for Large Leaf Elepidotes.

For large leaf elepidote hybrid Rhododendrons we have discovered fertile triploids and the offspring of these triploids can be tetraploids. For instance, Rhododendron 'Countess of Derby', which is a 1913 Henry White hybrid documented as 'Pink Pearl' x 'Cynthia', has been determined to be a tetraploid. Both 'Pink Pearl' and 'Cynthia' have been determined to be triploids. See It is 1913 So What Do You Do? by John and Sally Perkins. See Fertile Triploids. See Pink Pearl.

For large leaf elepidote hybrid Rhododendrons we have discovered tetraploids can produce diploid offspring in the first generation. See Super Reduced Meiosis.

Although there are no known polyploid elepidote species, many elepidote hybridizers, including Barlup, Bones, Brack, Briggs, Brockenbrough, Broughton, Bruns, Colombel, Croux and Fils, de la Sablière, Endtz, Evans, Felix and Dijkhuis, Fujioka, Greer, Gehnrich, Hachmann, Hartman, Heinje, Henny and Wennekamp, Hobbie, Kavka, Kehr, Korn, Koster, Lem, Loder, Lofthouse, Mangles, Markeeta, McCullough, Mossman, Murcott, Naylor, Patterson, Pearce, Rabideau, Sanders, Schannen, Seabrook, Standish and Noble, Stead, Stockman, Thornton, vanNes, VanVeen, von Martin, Walton, Waterer, White, Whitney, Wilson, and Woodward have worked with or produced ployploid elepidotes hybrids and in some cases are best known for these polyploid hybrids.

Clarence Towe aided us in confirming that the plant pictured above is 'Margaret Abbott'.

To see a poster on the ploidy results (Click on the poster image to enlarge):

Ploidy Research Poster by José Cerca Oliveira.

To see the research team:

Research Team of Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, and Mariana Castro.

To see other images of Frank Abbott's azaleas visit the following:

Abbott Azaleas by S & J Perkins.

The "In The Collections" web page of the Arnold Arboretum includes a reference to our ploidy research.

Summary of Ploidy Levels

Diploid Rhododendron molle,
Diploid Rhododendron prinophyllum,
Diploid 'Frank Abbott',
Diploid "Jane Abbott" (grex),
Diploid 'Nancy Evans',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Tetraploid Rhododendron calendulaceum,
Tetraploid 'Countess of Derby',
Tetraploid 'Horizon Monarch',
Tetraploid 'Margaret Abbott',
Tetraploid 'Point Defiance'

Source: John Abbott

Ploidy Results by Groups

Rhododendron Species,
Diploid Deciduous Azaleas,
Triploid Deciduous Azaleas,
Tetraploid Deciduous Azaleas,
Diploid Large Leaf Elepidotes,
Triploid Large Leaf Elepidotes,
Tetraploid Large Leaf Elepidotes,
Diploid Lepidotes,
Triploid Lepidotes,
Tetraploid Lepidotes,
Diploid Everegreen Azaleas,
Triploid Evergreen Azaleas,
Diploids,
Triploids,
Fertile Triploids,
Tetraploids,
Ghents,
Northern Lights, and
Rusticas

The following people and organizations donored samples for this reasearch:

John Abbott,
Vivian Abney of East Fork Nursery,
Arnold Arboretum,
Audra State Park,
Bartlett Arboretum,
Jim Barlup,
Bruce Clyburn,
Jane Brooks,
Joe Bruso,
Werner Brack,
Ned Brockenbrough,
Canobie Lake, NH,
Dick Cavender,
Connecticut College Arboretum,
Marc Colombel,
Mike Creel,
Al Fitzburg,
Robert Fox,
Harold Greer of Greer Gardens,
George Hibben,
Highstead Arboretum,
Don Hyatt,
Lindy Johnson of Appalachian Native Plants,
Richard Jaynes of Broken Arrow Nursery,
Doug Jolley,
Fred Knippel,
Longwood Gardens,
Ron Miller,
Dick Murcott,
Planview Nursery,
John and Sally Perkins,
Ron Rabideau of RareFind Nursery,
Ellie Sather of Whitney Gardens,
Stoddard Blog, NH,
John Thornton,
Hendrik Van Oostand of Azaleatuin,
Kathy Van Veen of Van Veen Nursery

John and Sally Perkins

"Medium Blue" is a Tetraploid

Rhododendron "Medium Blue", which is a Rhododendron augustinii hybrid under evaluation by Rarefind Nursery, 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.

Summary of Ploidy Levels

Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Purple Gem',
Tetraploid 'Blue Baron',
Tetraploid 'Blue Ridge',
Tetraploid 'Epoch',
Tetraploid 'Epoch' X Rhododendron augustinii,
Tetraploid "Medium Blue",
Tetraploid Rhododendron augustinii

Source: RareFind Nursery

John and Sally Perkins

June Newsletter

Have a great summer!

'Epoch' X augustinii is a Tetraploid

Rhododendron 'Epoch' X Rhododendron augustinii, which is a Kehr hybrid, 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.

Summary of Ploidy Levels

Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Purple Gem',
Tetraploid 'Blue Baron',
Tetraploid 'Blue Ridge',
Tetraploid 'Epoch',
Tetraploid 'Epoch' X Rhododendron augustinii,
Tetraploid "Medium Blue",
Tetraploid Rhododendron augustinii

Source: RareFind Nursery

John and Sally Perkins

Creel Demonstrates Rule #4

In June 2007 Mike Creel wrote the following:

"I well-pollinated two different Mountain Flame Azaleas - 'Gamecock' and 'Walhalla Gold' - with fresh pollen from a nearby eastmanii this May, and NONE of the flowers formed a seed pod, acting like they had never been pollinated."

"Can anyone try to explain this apparent incompatibility between calendulaceum and eastmanii?"

"A friend of mine in Oregon has had several successes with crossing occidentale and eastmanii, so those species appear compatible."

Answer to the Question.

The Mountain Flame Azalea, Rhododendron calendulaceum, is a tetraploid and a member of the tetraploid clade of deciduous azaleas.

Rhododendron eastmanii and Rhododendron occidentale are diploids and members of the diploid clade of deciduous azaleas.

By Rule #2, Rhododendron occidentale will accept pollen from Rhododendron eastmanii.

Rule #2: Species within a given clade freely cross in both directions. The resulting offspring are normally viable and fertile. The offspring normally reflect characteristics that are intermediate between the 2 species involved.

By Rule #4, Rhododendron calendulaceum will reject pollen from Rhododendron eastmanii.

Rule #4: Species in the tetraploid clade normally reject pollen from species of the diploid clade. Exceptions occur but they are extremely rare.

By Rule #3, Rhododendron eastmanii would accept pollen from Rhododendron calendulaceum.

Rule #3: Species in the diploid clade freely accepts pollen from species in the tetraploid clade. The resulting offspring are often viable but usually sterile (bloom but do not produce seed) triploids. The offspring often reflect more characteristics of the tetraploid pollen parent. Offspring having pink or salmon colored flowers with a yellow blotch are not unusual. Deformed anthers, multiple petals and color streaks in the corolla are also frequently seen.

Read Rules of Engagement.

John and Sally Perkins

'Blue Baron' is a Tetraploid

Rhododendron 'Blue Baron', which is a Mezitt hybrid documented as ['Starry Night' ('Gletschernacht') x 'Waltham'], 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.

Some question whether Rhododendron 'Blue Baron' has Rhododendron 'Waltham' as the pollen parent.

Summary of Ploidy Levels

Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Purple Gem',
Tetraploid 'Blue Baron',
Tetraploid 'Blue Ridge',
Tetraploid 'Epoch',
Tetraploid 'Epoch' X Rhododendron augustinii,
Tetraploid "Medium Blue",
Tetraploid Rhododendron augustinii

Source: RareFind Nursery

John and Sally Perkins

'Blue Ridge' is a Tetraploid

Rhododendron 'Blue Ridge', which is a Haag hybrid documented as 'Russautinii' X Rhododendron augustinii, 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.

Summary of Ploidy Levels

Triploid 'April Rhapsody',
Triploid 'Bluenose',
Triploid 'Purple Gem',
Tetraploid 'Blue Baron',
Tetraploid 'Blue Ridge',
Tetraploid 'Epoch',
Tetraploid 'Epoch' X Rhododendron augustinii,
Tetraploid "Medium Blue",
Tetraploid Rhododendron augustinii

Source: RareFind Nursery

John and Sally Perkins

'Pink Prelude' is a Diploid

Rhododendron 'Pink Prelude', which is a Watson hybrid documented as ('Sarita Loder' x Rhododendron calophytum) x Rhododendron macabeanum, 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 'Pink Prelude'

Source: RareFind Nursery

John and Sally Perkins

Field trip date change

The Chapter Field Trip to Cochato Nursery in Holbrook has been moved from Saturday June 25 to Sunday June 26 to avoid a conflict with the P4M meeting on Saturday.

To remind you about this trip, here is the squib (with the new date) from the May Newsletter:

FIELD TRIP TO COCHATO NURSERY

 

--  Mark your calendars Sunday June 26 10:30 a.m.  --

After our inspiring lecture on hostas in February a number of members expressed interest in going to Cochato Nursery, owned by our speakers Chuck Doughty and Sue DuBrava.   They are open Thursday - Sunday, from 9 to 5.  Let us plan to meet there about 10:30 a.m. on Sunday,  June 26 (to avoid the worst of the traffic), and by all means carpool.  To reach them take Rte 128 Braintree Exit 6 to Rte. 37S.  They are 5 miles from exit, just over the Holbrook line. .  This nursery is located at 373 North Franklin St., Holbrook MA (781.767.9770). Afterwards, we can find a place for lunch.

Their website is www.cochatonursery.com.

'Evening Sun' is a Triploid

Rhododendron 'Evening Sun', which is a Earl Sommerville introduction documented as Rhododendron austrinum or austrinum hybrid, 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

Triploid 'Evening Sun',
Tetraploid Rhododendron austrinum,
Tetraploid 'Earl's Gold',
Tetraploid 'Sommerville Sunrise'

Source: RareFind Nursery

John and Sally Perkins

Reminder: Board Meeting @ Wed Jun 8 7:30pm - 9pm (John Perkins)

more details » Board Meeting When Wed Jun 8 7:30pm – 9pm Eastern Time Where Hardings (map) Calendar John Perkins Who • John.A.Perkins@gmail.com - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you set a reminder for this event on the calendar John Perkins. You can change your reminders for specific events in the event details page in https://www.google.com/calendar/.

Filtering Ploidy Results by Multiple Labels

A few of you may wish to locate blog posts in the Rosebay Blog using multiple
labels. For instance all posts that have both the label elepidote and the label 4x
will be returned by the following

http://rosebayblog.blogspot.com/feeds/posts/full/-/elepidote/4x?max-results=999

To use this trick you must know the syntax for the trick and the labels used by
the Rosebay Blog

Notice you can filter by as many labels as you wish.

Using the syntax and the labels elepidote, 4x, and Greer gives all posts where
all three labels are used is here.

http://rosebayblog.blogspot.com/feeds/posts/default/-/elepidote/4x/Greer?max-results=999

The list of labels used by the Rosebay Blog is here

http://rosebayblog.blogspot.com/search/label/zzlabels

You have the power of a database once you have labels.

John and Sally Perkins

"Miller's pink austrinum" is a Tetraploid

Rhododendron "pink austrinum" 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.

According to Ron Miller, Rhododendron "pink austrinum" exists as populations containing no yellow Rhododendron austrinum on the Yellow River in Florida. No decision has been made to whether this is a species separate from Rhododendron austrinum, a subspecies of Rhododendron austrinum, or a merely a pink form or variety of Rhododendron austrinum. Populations containing both pink tetraploids and yellow tetraploids resembling Rhododendron austrinum also exist. These tetraploid populations are not colocated with any diploid populations that bloom at the time the tetraploids are in bloom. There are no triploids in these populations.

Rhododendron "pink austrinum" 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 atlanticum,
Tetraploid Rhododendron austrinum,
Tetraploid Rhododendron calendulcaeum,
Tetraploid Rhododendron colemanii,
Tetraploid Rhododendron luteum,
Tetraploid Rhododendron "pink austrinum"

Source: Ron Miller

John and Sally Perkins

"Coleman's May Pink" is a Tetraploid

Rhododendron colemanii "Coleman's May Pink" 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.

Summary of Ploidy Levels

Tetraploid Rhododendron colemanii,
Tetraploid Rhododendron colemanii "Coleman's May Pink"

Source: Connecticut College Arboretum

John and Sally Perkins

Rhododendron colemanii is a Tetraploid

Rhododendron colemanii 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 colemanii 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 atlanticum,
Tetraploid Rhododendron austrinum,
Tetraploid Rhododendron calendulcaeum,
Tetraploid Rhododendron colemanii,
Tetraploid Rhododendron colemanii "Coleman's May Pink",
Tetraploid Rhododendron luteum,
Tetraploid Rhododendron "pink austrinum"

Source: John Thornton

John and Sally Perkins

'Dawn's Early Light' is a Diploid

Rhododendron 'Dawn's Early Light', which is documented as a Rhododendron keiskei X Rhododendron xanthocodon, 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.

Both documented parents of Rhododendron 'Dawn's Early Light' are yellow, and the resemblance to Rhododendron keiskei is completely obvious, but there is little other evidence of the Rhododendron xanthocodon parent.

Summary of Ploidy Levels

Diploid Rhododendron keiskei,
Diploid 'Dawn's Early Light'

Source: RareFind Nursery

John and Sally Perkins

Reminder: Rhododendron Walk Hort Farm @ Sat Jun 4 10am - 12pm (John Perkins)

more details » Rhododendron Walk Hort Farm June 11, 2011 10 A.M. to Noon Rhododendron Walk and Talk with Hal Bill, Collection Curator. A great opportunity to tour the Rhododendrons and Eastern U.S. Native Azalea collections in bloom. These "Jewels in the Crown" are one of best collections in New England. This event takes place at Friends of Hort Farm in Burlington, VT. When Sat Jun 4 10am – 12pm Eastern Time Where Friends of Hort Farm, Burlington, VT (map) Calendar John Perkins Who • John.A.Perkins@gmail.com - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you set a reminder for this event on the calendar John Perkins. You can change your reminders for specific events in the event details page in https://www.google.com/calendar/.

Rhododendron calostrotum X carolinanum is a Diploid

Rhododendron calostrotum X Rhododendron minus Carolinanum Group 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 Rhododendron minus,
Diploid Rhododendron calostrotum X Rhododendron minus Group Carolinanum,
Diploid 'Robert Seleger'

Source: RareFind Nursery

John and Sally Perkins

Reminder: Board Meeting @ Wed Jun 8 7:30pm - 9pm (John Perkins)

more details » Board Meeting When Wed Jun 8 7:30pm – 9pm Eastern Time Where Hardings (map) Calendar John Perkins Who • John.A.Perkins@gmail.com - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you set a reminder for this event on the calendar John Perkins. You can change your reminders for specific events in the event details page in https://www.google.com/calendar/.

'Robert Seleger' is a Diploid

Rhododendron 'Robert Seleger', which is a Dietrich Hobbie hybrid documented as a Rhododendron calostrotum ssp. keleticum 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 Rhododendron calostrotum X Rhododendron minus Group Carolinanum,
Diploid 'Robert Seleger'

Source: RareFind Nursery

John and Sally Perkins