Index

R. 'Rotgold x Amaretto'

Rhododendron Hybrid

R. 'Rotgold' X R. 'Amaretto'

Hybridized By: No hybridiser registered

R. 'Rotha'

Rhododendron Hybrid

? X ?

Hybridized By: Unknown

R. 'Rothenburg'

Rhododendron Hybrid

R. 'Diane' X R. williamsianum

Hybridized By: von Martin, V.. Rothenburg/Oberlausitz, Germany, 1944

R. 'Rothschild Supreme'

Azalea Hybrid

? X ?

Hybridized By: Unknown

R. rothschildii

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Falconera

R. 'Rotkäppchen'

Rhododendron Hybrid

R. 'Ruth Otte' X R. 'Hachmann's Feuerschein'

Hybridized By: Hachmann, Hans. Barmstedt in Holstein, Germany, 1979

R. 'Rotraud'

Rhododendron Hybrid

R. clementinae X R. 'Erato'

Hybridized By: Hachmann, Hans. Barmstedt in Holstein, Germany, 1987

R. 'Rotstein'

Azalea Hybrid

? X ?

Hybridized By: VEG Saatzucht Zierplanzen Erfurt, 1986

R. 'Rouge Group'

Rhododendron Cultivar group

? X ?

Hybridized By: Rothschild, L. de. Founder of Exbury Gardens, UK

R. 'Rougemont'

Rhododendron Hybrid

? X ?

Hybridized By: Unknown

R. 'Rouseabout'

Vireya Hybrid

R. aurigeranum ssp aurigeranum X R. christianae

Hybridized By: Unknown

R. rousei

Species

Subgenus: Rhododendron
Section: Vireya
Subsection: Euvireya

R. 'Rover Group'

Rhododendron Cultivar group

? X ?

Hybridized By: Aberconway, Lord. Bodnant, Tal-y-Cafn, Wales

R. 'Rowena'

Rhododendron Hybrid

? X ?

Hybridized By: Ramsden, Sir John. Muncaster Castle, UK

R. 'Rowena Knight'

Vireya Hybrid

? X ?

Hybridized By: Oldham, B.E., 1993

R. 'Rowland P. Cary'

Rhododendron Hybrid

R. brachycarpum ssp brachycarpum X R. 'Van der Hoop'

Hybridized By: Cary, E.A., 1953

R. roxieanum var cucullatum

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Taliensia

R. roxieanum var oreonastes

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Taliensia

R. roxieanum var parvum

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Taliensia

R. roxieanum var roxieanum

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Taliensia

R. roxieoides

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Taliensia

R. 'Roy Blackmore'

Rhododendron Hybrid

R. 'Maverick' X R. 'Orchid Bouquet'

Hybridized By: Barlup, Jim. Bellevue, USA, 2014

R. 'Roy Hudson'

Rhododendron Hybrid

R. burmanicum X R. nuttallii

Hybridized By: Kerrigan, Howard, 1970

R. 'Roy Stockman'

Rhododendron Hybrid

? X ?

Hybridized By: Stockman, M.. Port Angeles, Washington, USA

R. 'Royal Beauty Group'

Rhododendron Hybrid

R. 'Lady Rosebery Group' X R. cinnabarinum ssp cinnabarinum Roylei Group

Hybridized By: Digby, Lord, 1936

R. 'Royal Blood'

Rhododendron Hybrid

R. elliottii X R. 'Rubens'

Hybridized By: Hanger, F.E.W.. RHS Garden, Wisley, Surrey, England, 1947

R. 'Royal Bouquet'

Vireya Hybrid

X R. superbum ssp superbum

Hybridized By: Unknown

R. 'Royal Command'

Azalea Hybrid

? X ?

Hybridized By: Exbury | The Rothschild Estate, Hampshire | England, 1958

R. 'Royal Flush Group'

Rhododendron Cultivar group

R. cinnabarinum ssp cinnabarinum X R. maddenii ssp maddenii

Hybridized By: Williams, John Charles. Caerhays, Cornwall, England, 1926

R. 'Royal Fusilier'

Rhododendron Hybrid

R. arboreum ssp nilagiricum 'Noyo Chief' X R. elliottii

Hybridized By: O'Rourke, H.. Burnie, Tasmania, Australia, 1982

R. 'Royal Gala'

Vireya Hybrid

R. aurigeranum ssp aurigeranum X

Hybridized By: Unknown

R. 'Royal Lodge'

Azalea Hybrid

? X ?

Hybridized By: Exbury | The Rothschild Estate, Hampshire | England, 1947

R. 'Royal Lodge x Fireball'

Azalea Hybrid

R. 'Royal Lodge' X R. 'Fireball'

Hybridized By: No hybridiser registered

R. 'Royal Mail'

Rhododendron Hybrid

R. 'Romany Chai Group' X R. 'Tally Ho Group'

Hybridized By: Slocock, Walter C.. Goldsworth Nursery, Woking, UK, 1946

R. 'Royal Pillow'

Azalea Hybrid

? X ?

Hybridized By: Unknown

R. 'Royal Pink'

Rhododendron Hybrid

R. 'Homer I' X R. williamsianum

Hybridized By: Hobbie, Dietrich G.. Westerstede/Linswege, Germany, 1945

R. 'Royal Purple'

Rhododendron Hybrid

? X ?

Hybridized By: No hybridiser registered, 1942

R. 'Royal Ruffles'

Rhododendron Hybrid

X

Hybridized By: Sanders, D., 1985

R. 'Royal Treasure'

Rhododendron Hybrid

R. 'Kubla Khan' X R. 'Ayers Rock'

Hybridized By: O'Rourke, H.. Burnie, Tasmania, Australia, 1985

R. 'Royal Windsor'

Rhododendron Hybrid

R. 'Jutland Group' X R. 'Royal Blood'

Hybridized By: Crown Estate Commissioners. Windsor, Berkshire, England, 1975

R. 'Royalty Group'

Rhododendron Cultivar group

? X ?

Hybridized By: Aberconway, Lord. Bodnant, Tal-y-Cafn, Wales

R. 'Royce Sproull'

Azalea Hybrid

? X ?

Hybridized By: Cole, D.J.

R. 'Roylei'

Rhododendron Hybrid

? X ?

Hybridized By: Liebig, L.L.. Dresden, Germany, 1860

R. 'Royston Festival'

Rhododendron Hybrid

? X ?

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada

R. 'Royston Frost'

Rhododendron Hybrid

? X ?

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada, 1950

R. 'Royston Opaline'

Rhododendron Hybrid

? X ?

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada, 1950

R. 'Royston Peach'

Rhododendron Hybrid

? X ?

Hybridized By: Unknown

R. 'Royston Radiance'

Rhododendron Hybrid

? X ?

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada, 1950

R. 'Royston Red'

Rhododendron Hybrid

R. forrestii Repens Group X R. thomsonii ssp thomsonii

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada, 1970

R. 'Royston Regency'

Rhododendron Hybrid

R. auriculatum X R. 'Fabia Group'

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada, 1950

R. 'Royston Reverie'

Rhododendron Hybrid

R. auriculatum X R. 'Fabia Group'

Hybridized By: Greig, E,J. & M.. Royston Nurseries, Vancouver Island, BC, Canada, 1980