| No. | Cultivar Name | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
|
1
| 'Radio Waves' | Med-Green | | - | Hybrid | Pale-Lavender | August | Johnson, Greg | .2004 |
|
2
| 'Rain Forest Shooting Stars' | Dark-Green | Medial | Yellow | Sport | Med-Lavender | July into August | Owens, William & Owens, Jean | .2008 |
|
3
| 'Rainbow' | Dark-Green | Marginal | Yellow | Sport | Pale-Lavender | July into August | Unknown | --NR-- |
|
4
| 'Raspatini' | Med-Green | | - | Hybrid | Light-Purple | August | Zilis, Mark | .2009 |
|
5
| 'Razzmatazz' | Med-Green | Marginal | White | Hybrid | Pale-Lavender | July into August | Beilstein, Doug & Beilstein, Mardy | .2013 |
|
6
| 'Red Bull' | Med-Green | | - | Hybrid | Unknown | July into August | Van Eechaute, Danny | .2010 |
|
7
| 'Red Rover' | Med-Green | | - | Hybrid | Med-Lavender | August to September | Moore, Jeff & Schwarz, Jim | .2015 |
|
8
| 'Reddish Dot' | Med-Green | | - | Hybrid | Deep-Purple | July into August | Liu, Donghuan | .2016 |
|
9
| 'Redneck Mardi Gras' | Yellow | | - | Unknown | Deep-Purple | August to September | Duncan, Mary Jo | .2016 |
|
10
| 'Resonance' | Dark-Green | Marginal | Creamy White | Hybrid | Light-Purple | August | Aden, Paul | .1976 |
|
11
| 'Revenge' | Med-Green | Streaked | Yellow | Unknown | Unknown | Unknown | Williams, Glenn | --NR-- |
|
12
| 'Reverend Mac' | Blue/Green | | - | Sport | Pale-Lavender | July into August | Van Eechaute, Danny | .2011 |
|
13
| 'Richland Gold' | Yellow | | - | Sport | Pale-Lavender | July into August | Wade, Van | .1987 |
|
14
| 'Rippled Honey' | Med-Green | | - | Hybrid | Light-Purple | August | Benedict, Dr Ralph (Herb) & Ruh, Peter | .2005 |
|
15
| 'Rippled Treasure' | Med-Green | | - | Hybrid | Unknown | June into July | Zilis, Mark | .2010 |
|
16
| 'Risa' | Med-Green | | - | Unknown | Med-Lavender | July into August | Dupre, Dirk | .2006 |
|
17
| 'Rock and Beautiful Ears' | Light-Green | Marginal | White | Sport | Med-Lavender | July | Wade, Van | --NR-- |
|
18
| 'Rock of Gibralter' | Blue/Green | | - | Sport | Unknown | June into July | Zilis, Mark | .2010 |
|
19
| 'Rocket City' | Yellow | | - | Unknown | Unknown | - | Goodwin, Randy | .2014 |
|
20
| 'Rough Lemon' | Yellow | | | Hybrid | Light-Purple | July into August | Solberg, Robert | .2022 |
|
21
| 'Roughrider' | Med-Green | Marginal | White | Hybrid | Pure-White | August to September | Graves, Butch | .2008 |
|
22
| 'Royal Charmer' | Med-Green | Streaked | White | Sport | Pure-White | July into August | Van Eechaute, Danny | .2011 |
|
23
| 'Royal Empress' | Med-Green | Marginal | Chartreuse | Sport | Pale-Lavender | June into July | Rawson, Don | .2016 |
|
24
| 'Royal Standard' | Med-Green | | - | Hybrid | Pure-White | August September October | Grullemans, John J. & Wayside Gardens | .1986 |
|
25
| 'Royal Standard Double' | Med-Green | | - | Sport | Pure-White | August to September | Unknown | --NR-- |
|
26
| 'Ruffed Up' | Yellow | | - | Hybrid | Pale-Lavender | August to September | Carlson, Monty & Carlson, Julie | .2009 |
|
27
| 'Rutherford Birchard Hayes' | Light-Green | | - | Unknown | Med-Lavender | - | Ruh, Peter & Ruh, Jean | .2010 |
|