Index

R. 'Ringetsu'

Azalea Hybrid

? X ?

Hybridized By: No hybridiser registered, 1987

R. 'Ringgold'

Azalea Hybrid

? X ?

Hybridized By: Gable, J.B. | Stewartstown, Pennsylvania | USA

R. 'Rio'

Rhododendron Hybrid

R. 'Newburyport Beauty' X R. 'Newburyport Belle'

Hybridized By: Leach, Dr. David G.. North Madison, Ohio, USA, 1968

R. 'Rio de Janeiro'

Rhododendron Hybrid

? X ?

Hybridized By: Guyens, H.J.A.

R. 'Rio Rita'

Vireya Hybrid

R. 'Doctor Hermann Sleumer' X R. leucogigas

Hybridized By: Blumhardt, O. S.. Koromiko Nurseries, Whangarei, New Zealand, 1983

R. 'Ripe Corn'

Rhododendron Hybrid

R. 'Goldsworth Orange' X R. 'Exbury Naomi'

Hybridized By: Slocock, Walter C.. Goldsworth Nursery, Woking, UK, 1966

R. 'Ripe Peach'

Rhododendron Hybrid

R. 'C.O.D.' X R. 'Dexter's Honeydew'

Hybridized By: Knippenberg, Mrs. J. F., 1980

R. 'Riplet Group'

Rhododendron Hybrid

R. forrestii Repens Group X R. 'Letty Edwards Group'

Hybridized By: Lem Halfdan. Seattle, Washington, USA, 1961

R. ripleyi var basitrichum

Species

Subgenus: Rhododendron
Section: Vireya
Subsection: Euvireya

R. ripleyi var cryptogonium

Species

Subgenus: Rhododendron
Section: Vireya
Subsection: Euvireya

R. ripleyi var ripleyi

Species

Subgenus: Rhododendron
Section: Vireya
Subsection: Euvireya

R. ririei

Species

Subgenus: Hymenanthes
Section: Pontica
Subsection: Argyrophylla

R. 'Rising Sun'

Azalea Hybrid

? X ?

Hybridized By: Morrison, B.Y. | Pass Christian, Mississippi | USA

R. 'Risque'

Azalea Hybrid

? X ?

Hybridized By: Morrison, B.Y. | Pass Christian, Mississippi | USA

R. 'Rita Zvaigzne'

Azalea Hybrid

? X ?

Hybridized By: Kondratovičs, Rihard | Riga | Latvia

R. 'Ritchard's Red'

Rhododendron Hybrid

? X ?

Hybridized By: Delp Weldon E.. Harrisville, Pensylvania, USA

R. 'Ritchie'

Rhododendron Hybrid

R. catawbiense 'Catalgla' X R. 'Sappho'

Hybridized By: Delp Weldon E.. Harrisville, Pensylvania, USA, 1974

R. 'Ritchutissima'

Azalea Hybrid

? X ?

Hybridized By: Sunningdale Nursery

R. 'Ritenďtis'

Azalea Hybrid

? X ?

Hybridized By: Kondratovičs, Rihard | Riga | Latvia

R. 'Ritzy'

Rhododendron Hybrid

? X ?

Hybridized By: Smith, A.L.

R. 'Rival'

Azalea Hybrid

? X ?

Hybridized By: Pericat, A.

R. 'Rivermist'

Azalea Hybrid

R. 'Sherwoodii' X R. 'Fedora'

Hybridized By: Harris, J.O. | Lawrenceville, Georgia | USA, 1970

R. rivulare

Species

Subgenus: Tsutsusi
Section: Tsutsusi

R. 'Rixte'

Rhododendron Hybrid

R. 'Goldsworth Orange' X R. insigne

Hybridized By: Robeneck, H.. Westerstede, Germany, 1950

R. 'Road Red'

Rhododendron Hybrid

? X ?

Hybridized By: Steele, Captain Richard, M., 2001

R. 'Roadrunner'

Azalea Hybrid

? X ?

Hybridized By: Motzkau, H.W.

R. 'Rob's Favourite'

Vireya Hybrid

R. viriosum X R. macgregoriae

Hybridized By: Unknown

R. 'Robbie Robinson'

Rhododendron Hybrid

? X ?

Hybridized By: Unknown

R. 'Robbins Flame'

Azalea Hybrid

? X ?

Hybridized By: Arneson, Ivan & Robertha | Arneson Nursery, Canby, Oregon | USA

R. 'Robbo'

Rhododendron Hybrid

? X ?

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

R. 'Robby'

Rhododendron Hybrid

? X ?

Hybridized By: Delp Weldon E.. Harrisville, Pensylvania, USA

R. 'Robert Allison'

Rhododendron Hybrid

R. 'Caroline' X R. fortunei ssp discolor

Hybridized By: Gable, J.B.. Stewartstown, Pennsylvania, USA, 1938

R. 'Robert Balch'

Rhododendron Hybrid

R. arboreum ssp zeylanicum X R. elliottii

Hybridized By: Balch, R.W.. Parks & Garden Dept., Dunedin, New Zealand, 1960

R. 'Robert Bates'

Vireya Hybrid

X R. konori var konori

Hybridized By: Unknown

R. 'Robert Burns'

Rhododendron Hybrid

? X ?

Hybridized By: Noble, C.. Standish & Noble, Bagshot, Surrey, England, 1862

R. 'Robert Cobden'

Rhododendron Hybrid

? X ?

Hybridized By: Davies, I. Ormskirk, Lancashire, England, 1896

R. 'Robert Coe'

Rhododendron Hybrid

? X ?

Hybridized By: Dexter, C.O.. Sandwich, MA, USA, 1943

R. 'Robert Croux'

Rhododendron Hybrid

? X ?

Hybridized By: Croux & Fils. Châtenay-Malabry, France, 1899

R. 'Robert de Belder'

Rhododendron Hybrid

? X ?

Hybridized By: Böhlje G. D.. Westerstede, Germany

R. 'Robert de Schrijver'

Azalea Hybrid

? X ?

Hybridized By: Unknown

R. 'Robert Earl'

Azalea Hybrid

? X ?

Hybridized By: Greentree, M.E., 1985

R. 'Robert Fortune'

Rhododendron Cultivar group

R. griffithianum X R. 'H. M. Arderne'

Hybridized By: Williams, Percival D.. St Keverne, Cornwall, England, 1922

R. 'Robert Hale'

Rhododendron Hybrid

? X ?

Hybridized By: Sifferman, Karl I.. Seattle, Washington, USA, 1969

R. 'Robert Keir'

Rhododendron Hybrid

R. lacteum X R. 'Luscombei'

Hybridized By: Stevenson, J.B.. Ascot, Berkshire, England, 1951

R. 'Robert Koch'

Azalea Hybrid

R. 'Cecile' X

Hybridized By: Fleischmann, C. | Wiesmoor, Ostfriesland | Germany, 1970

R. 'Robert Korn'

Rhododendron Hybrid

R. 'Diane' X R. 'Gomer Waterer'

Hybridized By: Korn, R.. Renton, Washington, USA, 1969

R. 'Robert Louis Stevenson'

Rhododendron Hybrid

R. 'May Day Group' X R. 'Jester'

Hybridized By: Seabrook, Cecil S.. Tacoma, Washington, USA, 1967

R. 'Robert Schill'

Rhododendron Hybrid

R. 'Whitney’s Orange' X R. 'Golden Star'

Hybridized By: Rosenthal, J.. Jamaica, NY, USA, 1981

R. 'Robert Seleger'

Rhododendron Hybrid

R. calostrotum ssp keleticum X ?

Hybridized By: Hobbie, Dietrich G.. Westerstede/Linswege, Germany, 1960

R. 'Robert Sutherland'

Rhododendron Hybrid

R. 'R.O. Delp' X R. 'Golden Star x Mezitt's Hardy Yellow'

Hybridized By: Looye, Jack. Niagara on the Lake, Ontario, Canada, 1994

R. 'Robert van Oost'

Azalea Hybrid

R. 'Theodor Findeisen' X R. 'Paul Schäme'

Hybridized By: van Oost, G., 1941