| Cultivar Name | Plant Size | Origin | Flower Color | Season | Source | Registered |
| 'Cair Paravel' | Large | Hybrid | Pale-Lavender | July | Lysne, Rod | .2021 |
| 'Calea Autumn' | Small | Unknown | - | - | Unknown | --NR-- |
| 'Canary Diamond' | Medium | Unknown | - | - | Vincun, Rachel | --NR-- |
| 'Candlelight' | Large | Hybrid | Near-White | June | Ward, Dr Dick & Ward, Jane | .2005 |
| 'Cardwell Yellow' | Large | Unknown | Near-White | June into July | Krossa, Gus & Ruh, Peter | .1981 |
| 'Carolina Keepsake' | Small | Hybrid | - | August to September | Solberg, Robert | .2016 |
| 'Carpenter Gold' | Small | Unknown | - | - | Unknown | --NR-- |
| 'Carved Complexity' | Large | Hybrid | Near-White | June into July | McDonell, Harold | .2014 |
| 'Cassandra' | Small | Hybrid | Light-Purple | July | Wagner, Wally | .1985 |
| 'Celebration of Angels' | Medium | Sport | Med-Lavender | - | Balitewicz, Bob | --NR-- |
| 'Celery Satin' | Small | Sport | Med-Lavender | July | Snyder, Ron | .2001 |
| 'Centerfold' | Large | Unknown | Pale-Lavender | June into July | Kamp, Gayle | .1994 |
| 'Cha Cha Cha' | - | Unknown | - | - | Vincun, Rachel | --NR-- |
| 'Chalice of Gold' | Large | Hybrid | Pale-Lavender | June into July | Elslager, Ed | .2004 |
| 'Changing Moods' | Small | Hybrid | Pale-Lavender | August to October | Vaughn, Kevin | .1983 |
| 'Charlie's Angels' | Large | Sport | Pale-Lavender | June | Zilis, Mark | .2009 |
| 'Chartreuse Domes' | Large | Unknown | Pale-Lavender | July into August | Livingston, Ron | --NR-- |
| 'Chartreuse Fountain' | Medium | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Chartreuse Piecrust' | Large | Hybrid | Near-White | July | Owens, Clarence | .1985 |
| 'Chartreuse Waves' | Small | Hybrid | - | - | Aden, Paul & Zilis, Mark | .2010 |
| 'Chartreuse Wiggles' | Small | Hybrid | Light-Purple | August | Aden, Paul | .1976 |
| 'Cheatin Heart' | Small | Hybrid | Light-Purple | July | Zumbar, Wm | .1995 |
| 'Checkered Cab' | Medium | Unknown | - | July into August | Beilstein, Doug & Beilstein, Mardy | .2012 |
| 'Cherry Tart' | Small | Unknown | Light-Purple | August | Scheer, Alttara | --NR-- |
| 'Chesieres Yellow Masquerade' | Small | Sport | Light-Purple | June into July | Hirsbrunner, Liselotte | --NR-- |
| 'Chesterland Gold' | Medium | TC Sport | Pale-Lavender | July into August | Zilis, Mark & Ruh, Peter | .1997 |
| 'China Gold' | Large | Hybrid | - | - | Goodenough, Rick | --NR-- |
| 'Chinese Gold' | Medium | Hybrid | - | August to September | Wade, Van & Walek, Kevin | .2009 |
| 'Choo Choo Train' | Large | Unknown | Pale-Lavender | July | Avent, Tony | .1999 |
| 'Chorus Girl' | Medium | Hybrid | Near-White | June into July | Beilstein, Doug & Beilstein, Mardy | .2013 |
| 'Chris' | Large | Unknown | - | June into July | Schwarz, Jim & Schwarz, Karen | .2014 |
| 'Christmas Gold' | Large | Sport | Pale-Lavender | July | Seaver, Mildred & Walek, Kevin | .2009 |
| 'Chromosphere' | Medium | Hybrid | - | July into August | Zilis, Mark | .2010 |
| 'Citric Star' | Small | Unknown | Pale-Lavender | July into August | Vissers, Louis | .2017 |
| 'City Lights' | Large | Hybrid | Near-White | June into July | Aden, Paul | .1978 |
| 'Claire de Lune' | Small | Unknown | - | - | O'Harra, Russ | --NR-- |
| 'Coconut Custard' | Miniature | Hybrid | Med-Lavender | July into August | Solberg, Robert | .2007 |
| 'Code Red' | Small | Unknown | - | - | Unknown | --NR-- |
| 'Collector's Gold' | Large | Unknown | - | - | Janssen, Bill | --NR-- |
| 'Colleen Marie' | Large | Hybrid | Pale-Lavender | June into July | Kwick, Charles | .2017 |
| 'Combined Elegance' | Medium | Hybrid | Pale-Lavender | July into August | Kwick, Charles | .2019 |
| 'Community Chest' | Medium | Hybrid | - | - | Malloy, Alex | --NR-- |
| 'Connie Sun' | Large | Sport | Med-Lavender | July | Snyder, Ron | .2001 |
| 'Conventional Loss' | Large | Unknown | - | - | Unknown | --NR-- |
| 'Cookie Monster' | Large | Hybrid | - | - | Kuk, Bob | --NR-- |
| 'Cool Change' | Large | Hybrid | Near-White | June into July | Kuk, Bob | .1995 |
| 'Copa Cabana' | Medium | Hybrid | Pale-Lavender | July | Terpening, Kent | .2021 |
| 'Corn Muffins' | Large | Hybrid | Light-Purple | July into August | Beilstein, Doug & Zilis, Mark | .2009 |
| 'Country Boy' | Large | Unknown | - | - | Ziarek, Ken | --NR-- |
| 'Country Corn' | Large | Unknown | Near-White | July | Dye, Kay | .2017 |
| 'Country Sun Drop' | Medium | Unknown | Light-Purple | July into August | Spece, Josh | .2020 |
| 'Cream Edger' | Small | Sport | Pale-Lavender | June into July | Lewis, Alan | --NR-- |
| 'Crème Solaire' | Medium | Unknown | Near-White | June | Deckert, Emile & Deckert, Jane | .2004 |
| 'Crinkle Cup' | Large | Hybrid | Pale-Lavender | June into July | Fisher, Eunice V. | .1971 |
| 'Crinkles' | - | Hybrid | - | - | Goodwin, Randy | --NR-- |
| 'Crispy Critters' | Small | Unknown | - | - | Avent, Tony | --NR-- |
| 'Crossing the Rubicon' | Medium | TC Sport | - | June into July | Zilis, Mark | .2009 |
| 'Crossword Puzzle' | Large | Unknown | Med-Lavender | - | Beilstein, Doug | --NR-- |
| 'Crystal Fountain' | Large | Sport | Light-Purple | July | Banyai, Bruce | .1999 |
| 'Cup of Cream' | Small | Unknown | - | - | Woods, Doyle | --NR-- |
| 'Cup of Gold' | Medium | Unknown | - | - | Wade, Van | --NR-- |
| 'Cup of Joy' | Medium | Hybrid | Near-White | July | Myers, Gary | .2011 |
| 'Curious Yellow' (Livingston) | Small | Unknown | Light-Purple | - | Livingston, Ron | --NR-- |
| 'Curious Yellow' (M. Seaver) | Medium | Unknown | - | - | Seaver, Mildred | --NR-- |
| 'Curve Ball' | Large | Hybrid | Near-White | June into July | Ward, Dr Dick & Ward, Jane | .2009 |
| 'Cute Little Delores' | Small | Unknown | - | July into August | Freeman, Franc | .2009 |
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