| Medium Size Hostas | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'C. C. Ryder' | Blue/Green | Marginal | White | Unknown | - | - | Stygall, Patsy & Crockett, Clyde | --NR-- |
| 'Cabaret' | Dark-Green | Marginal | White | Nat-Sport | Med-Lavender | July into August | Hansen, Hans | --NR-- |
| 'Cabin Boy' | Light-Green | - | - | Hybrid | Light-Purple | July into August | Kwick, Charles | .2017 |
| 'Cadillac' | Yellow | Marginal | Blue-Green | Unknown | Near-White | July | Avent, Tony & Skrocki, Ed | .1998 |
| 'Caesar' | Yellow | Marginal | Green | Nat-Sport | Pale-Lavender | July | Malloy, Alex | .1999 |
| 'Caesar Salad' | Med-Green | - | - | Hybrid | Pale-Lavender | July into August | Avent, Tony | .2007 |
| 'Cajun Sunrise' | Yellow | Streaked | Yellow | Hybrid | Pale-Lavender | July into August | Elslager, Ed | .2000 |
| 'Calico Cat' | Blue/Green | Streaked | Speckles | Unknown | - | - | Duback, Robyn | --NR-- |
| 'California Dreamin' | Light-Green | Marginal | Yellow | Unknown | - | - | Meyer, Bill & Brashear, Carol | --NR-- |
| 'Cambria Blue' | Blue/Green | - | - | Unknown | - | - | Benedict, Dr Ralph (Herb) | --NR-- |
| 'Camelot' | Blue/Green | - | - | Unknown | Pale-Lavender | July | Smith, Eric & BHHS | .1988 |
| 'Camouflage' | Med-Green | Marginal | Green | Nat-Sport | Pale-Lavender | July | Chatto, Beth | --NR-- |
| 'Campfire' | Blue/Green | Streaked | Yellow | Nat-Sport | Med-Lavender | August | Zilis, Mark | .2011 |
| 'Canadian Shield' | Dark-Green | - | - | Nat-Sport | Pale-Lavender | July into August | Knechtel, Ken | .1993 |
| 'Canary Diamond' | Yellow | - | - | Unknown | - | - | Vincun, Rachael | --NR-- |
| 'Candle Glow' | Light-Green | Streaked | Speckles | Hybrid | Pale-Lavender | July | Minks, Eldren | .1990 |
| 'Candle In The Dark' | Light-Green | Streaked | Yellow | Unknown | - | - | Asch, Stuart | --NR-- |
| 'Candy Hearts' | Blue/Green | - | - | Hybrid | Pale-Lavender | July | Fisher, Eunice V. & Ruh, Peter | .1998 |
| 'Candy Kisses' | Med-Green | - | - | Hybrid | Med-Lavender | August to October | Solberg, Robert & Shades of Green | .2013 |
| 'Canterbury Tales' | Med-Green | Marginal | White | Nat-Sport | Med-Lavender | July into August | Malloy, Alex | .2002 |
| 'Cape Cod' | Blue/Green | Marginal | Yellow | Unknown | - | - | Goodenough, Rick | --NR-- |
| 'Capitol Dome' | Light-Green | - | - | Hybrid | - | - | Minks, Eldren | .1980 |
| 'Capitol Hill' | Dark-Green | Marginal | Green | Nat-Sport | Med-Lavender | June into July | Avent, Tony | .2005 |
| 'Captain' | Blue/Green | Medial | White | Unknown | - | - | Unknown | --NR-- |
| 'Captain Teach' | Dark-Green | - | - | Hybrid | Med-Lavender | July into August | Sugita, Hajime & Ruh, Peter & Jean | .2001 |
| 'Captain's Adventure' | Light-Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Heemskerk, Gerardus | .2009 |
| 'Caravan' | Med-Green | Marginal | Yellow | Hybrid | Near-White | June into July | Ward, Dr Dick & Jane | .2012 |
| 'Cardboard' | Med-Green | - | - | Unknown | Pure-White | July into August | Livingston, Ron | --NR-- |
| 'Carder Blue' | Blue/Green | - | - | Unknown | Near-White | June into July | Carder, Ellen & AHS | .1986 |
| 'Carisa Nichole' | Blue/Green | Marginal | Yellow | Hybrid | Pale-Lavender | June into July | Byrd, I. | .2000 |
| 'Carnival' | Med-Green | Marginal | Yellow | Hybrid | Pale-Lavender | July into August | Lachman, Wm & Eleanor | .1986 |
| 'Carol' | Blue/Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Williams, Frances & AHS | .1986 |
| 'Carol and Martin' | Dark-Green | Streaked | Yellow | Nat-Sport | Pale-Lavender | July into August | Sawyer, Rick | --NR-- |
| 'Carolina Blue' | Blue/Green | - | - | Hybrid | Light-Purple | August | Solberg, Robert | .2000 |
| 'Carolina Moon' | Med-Green | Marginal | Yellow | Nat-Sport | Pale-Lavender | July into August | Breiwick, Al | .1997 |
| 'Carolina Sunshine' | Dark-Green | Marginal | Yellow | Hybrid | Light-Purple | July | Avent, Tony | .1999 |
| 'Carol's August Halo' | Med-Green | Marginal | Yellow | Nat-Sport | Pale-Lavender | July | Brashear, Carol | --NR-- |
| 'Carolyn On The Edge' | Med-Green | Streaked | Yellow | Unknown | - | - | Williams, Glenn | --NR-- |
| 'Carousel' | Med-Green | Marginal | Yellow | Hybrid | Pale-Lavender | August | Lachman, Wm & Eleanor | .1989 |
| 'Carriage Wheels' | Dark-Green | Medial | Yellow | Nat-Sport | Near-White | June into July | Summers, Alex & Walek, Kevin | .2009 |
| 'Carson' | Med-Green | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Cartwheels' | Blue/Green | Marginal | Yellow | Nat-Sport | Near-White | July | Summers, Alex & Ruh, Peter | .2002 |
| 'Caryl's Fancy' | Blue/Green | Marginal | Light Green | Unknown | - | - | Vaillancourt, Caryl | --NR-- |
| 'Cascades' | Blue/Green | Medial | White | Hybrid | Pure-White | July | Lachman, Wm & Eleanor | .1993 |
| 'Cascades Streaked' | Med-Green | Streaked | Speckles | Nat-Sport | Pure-White | July | Lachman, Wm & Eleanor | --NR-- |
| 'Cassanova' | Med-Green | Streaked | Speckles | Nat-Sport | Light-Purple | August | Seaver, Charles | --NR-- |
| 'Cat Scratch Fever' | Med-Green | - | - | TC Sport | Light-Purple | July | Zilis, Mark | --NR-- |
| 'Cathedral' | Light-Green | Marginal | White | Nat-Sport | Med-Lavender | July | Malloy, Alex | .2002 |
| 'Catherine' | Blue/Green | Medial | White | Nat-Sport | Med-Lavender | July into August | Heemskerk, Gerardus | .2011 |
| 'Catherine Ann' | Blue/Green | - | - | Hybrid | Pale-Lavender | June | Nyikos, Frank | .1999 |
| 'Catherine the Great' | Light-Green | - | | Unknown | Pale-Lavender | July into August | Goodwin, Randy | .2019 |
| 'Cathy's Clown' | Med-Green | Marginal | White | Unknown | - | June into July | Wasitis, Chick | .2011 |
| 'Cat's Meow' | Med-Green | Marginal | Chartreuse | Nat-Sport | Pure-White | June into July | Falstad, C.H | .1998 |
| 'Catskill' | Dark-Green | Marginal | Yellow | Hybrid | - | - | Malloy, Alex | --NR-- |
| 'Celebration' | Med-Green | Medial | White | Hybrid | Deep-Purple | - | Aden, Paul | .1978 |
| 'Celebration of Angels' | Yellow | - | - | Nat-Sport | Med-Lavender | - | Balitewicz, Bob | --NR-- |
| 'Celtic Dancer' | Med-Green | - | - | Hybrid | Pale-Lavender | July into August | Dean, Don | .2008 |
| 'Celtic Uplands' | Med-Green | - | - | Hybrid | Pale-Lavender | August | Dean, Don | .2005 |
| 'Center Glow' | Light-Green | Medial | Yellow | Unknown | - | - | Serafin, Viktoria | --NR-- |
| 'Center of Attention' | Med-Green | Medial | Creamy White | Hybrid | Light-Purple | July | Kulpa, John | .1999 |
| 'Cerulean Magic' | Blue/Green | - | - | Hybrid | - | June into July | Zilis, Mark | .2009 |
| 'Chado' | Med-Green | Marginal | White | Hybrid | Pale-Lavender | July | Johnson, Greg | .2004 |
| 'Chain Lightning' | Med-Green | Medial | White | Unknown | Pale-Lavender | July | Ward, Dr Dick & Jane | .1999 |
| 'Chameleon' (Smith) | Med-Green | - | - | Hybrid | - | - | Smith, Eric | --NR-- |
| 'Chameleon' (Unknown) | Med-Green | Streaked | Yellow | Hybrid | Med-Lavender | July into August | Unknown | --NR-- |
| 'Champagne for All' | Dark-Green | Medial | White | Nat-Sport | Pale-Lavender | July into August | Van Eechaute, Danny | .2015 |
| 'Champagne Toast' | Light-Green | Marginal | White | Hybrid | Near-White | June | Schroeder, R.&B. & Petryszyn, Olga | .2012 |
| 'Change of Tradition' | Blue/Green | Marginal | White | TC Sport | Pale-Lavender | August | Zilis, Mark | .1988 |
| 'Chantilly Lace' | Med-Green | Marginal | White | Hybrid | Pale-Lavender | August | Lachman, Wm & Eleanor | .1988 |
| 'Chariots of Fire' | Light-Green | Marginal | Yellow | Hybrid | Light-Purple | August to October | Dishon, Jim | .2004 |
| 'Charisma' | Dark-Green | Streaked | Yellow | Unknown | - | - | Asch, Stuart | --NR-- |
| 'Charity' | Dark-Green | Marginal | White | Nat-Sport | - | June into July | Silvers, Bill | .2011 |
| 'Charlie' | Blue/Green | Medial | Green | Nat-Sport | Near-White | July | Graves, Butch | .2008 |
| 'Chart Topper' | Blue/Green | - | - | Nat-Sport | Pale-Lavender | July into August | Zilis, Mark | --NR-- |
| 'Chartreuse Fountain' | Yellow | - | - | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Chartreuse Spoons' | Light-Green | - | - | Unknown | Pale-Lavender | July into August | Livingston, Ron | --NR-- |
| 'Checkered Cab' | Yellow | - | - | Unknown | - | July into August | Beilstein, Doug & Mardy | .2012 |
| 'Cheesehead No. 1' | Yellow | Streaked | Green | Nat-Sport | - | - | Unknown | --NR-- |
| 'Chelsea' | Med-Green | - | - | Nat-Sport | Light-Purple | July | Hadrava, Jerry | --NR-- |
| 'Cherries Jubilee' | Med-Green | Streaked | Speckles | Nat-Sport | Light-Purple | July into August | Malloy, Alex | .2001 |
| 'Cherry Berry' | Blue/Green | Marginal | White | Hybrid | Light-Purple | July into August | Lachman, Wm & Eleanor | .1991 |
| 'Cherry Berry Streaked' | Blue/Green | Streaked | Speckles | Nat-Sport | Light-Purple | July into August | Schmid, Tom | --NR-- |
| 'Cherry Flip' | Dark-Green | - | - | Hybrid | Light-Purple | August | Zilis, Mark & Solberg, Robert | .2012 |
| 'Cherry Pie' | Med-Green | Medial | White | Nat-Sport | Light-Purple | August to October | Machen, John | --NR-- |
| 'Chesieres Green Christmas' | Med-Green | Streaked | White | TC Sport | Med-Lavender | June into July | Hirsbrunner, Liselotte | .2002 |
| 'Chesterland Gold' | Yellow | - | - | TC Sport | Pale-Lavender | July into August | Zilis, Mark & Ruh, Peter | .1997 |
| 'Chichibu Genso Iwa' | Med-Green | Streaked | White | Nat-Sport | - | - | Kosasa | --NR-- |
| 'Chichibu-no-Hana Iwa' | Med-Green | Streaked | Yellow | Nat-Sport | - | - | Unknown | --NR-- |
| 'Chickadee' | Med-Green | Marginal | White | Unknown | Pure-White | August | Benedict, Dr Ralph (Herb) | --NR-- |
| 'Chicken' | Light-Green | - | - | Unknown | - | - | Belk, Al | --NR-- |
| 'Chickenhearted' | Light-Green | - | - | Hybrid | Pure-White | July into August | Groothuis, Mike | .2012 |
| 'Chiemsee Blaue Taube' | Blue/Green | - | - | Nat-Sport | Med-Lavender | - | Eschenbach, Volker | --NR-- |
| 'Chiemsee Class' | Med-Green | Medial | Yellow | Nat-Sport | Pale-Lavender | July | Eschenbach, Volker | --NR-- |
| 'Chiemsee Eisvogel' | Blue/Green | Marginal | Green | Nat-Sport | Pale-Lavender | July into August | Eschenbach, Volker | --NR-- |
| 'Chiemsee Glimmer' | Blue/Green | Streaked | Green | Nat-Sport | Pale-Lavender | July into August | Eschenbach, Volker | --NR-- |
| 'Chiemsee Schätzchen' | Blue/Green | - | - | Nat-Sport | Pale-Lavender | July into August | Eschenbach, Volker | --NR-- |
| 'Chiemsee Weihnachtssport' | Dark-Green | Medial | White | Nat-Sport | Pale-Lavender | July into August | Eschenbach, Volker | --NR-- |
| 'Child of the Queen' | Blue/Green | Medial | Yellow | Nat-Sport | - | - | van den Top, Jan | --NR-- |
| 'Childhood Fantasy' | Blue/Green | - | - | Hybrid | - | - | Livingston, Ron | --NR-- |
| 'Childhood Sweetheart' | Light-Green | Marginal | White | Hybrid | Pale-Lavender | August | Hansen, Hans | .2005 |
| 'Chinese Dragon' | Med-Green | Medial | Yellow | TC Sport | Near-White | June into July | Anderson, Jim | --NR-- |
| 'Chinese Dragon Streak' | Med-Green | Streaked | Speckles | Nat-Sport | Pale-Lavender | June | Anderson, Jim | --NR-- |
| 'Chinese Gold' | Yellow | - | - | Hybrid | - | August to September | Wade, Van & Walek, Kevin | .2009 |
| 'Chinese Jade' | Dark-Green | Marginal | Yellow | Unknown | - | - | Unknown | --NR-- |
| 'Chinese Sunrise' | Med-Green | Marginal | Greenish White | Nat-Sport | Pale-Lavender | August to September | Schaeffer, Robert & Ruh, Peter | .1992 |
| 'Chiquita' | Med-Green | - | - | Unknown | Pale-Lavender | July | Eisel, Mervin | .1979 |
| 'Chirifu Hime Tokudama' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | July | Unknown | --NR-- |
| 'Chirifu Ogon Himetokudama' | Med-Green | Marginal | - | Nat-Sport | Pale-Lavender | June into July | Unknown | --NR-- |
| 'Chivalry' | Blue/Green | - | - | Hybrid | Med-Lavender | July into August | Malloy, Alex | .2001 |
| 'Chodai Ginba' | Dark-Green | - | - | Unknown | Pale-Lavender | July | Kajigawa & Ruh, Peter | .2003 .2018 |
| 'Choko Nishiki' | Med-Green | - | - | Nat-Sport | Pale-Lavender | July | AHS & Zilis, Mark & Asami | .2012 |
| 'Chopsticks' | Med-Green | - | - | Hybrid | Light-Purple | September to October | Herold, Roy & Walek, Kevin | .2009 |
| 'Chorus Girl' | Yellow | - | - | Hybrid | Near-White | June into July | Beilstein, Doug & Mardy | .2013 |
| 'Chris' China Star' | Light-Green | - | - | Hybrid | - | - | Brinkmann, Christina | --NR-- |
| 'Christmas Candy' | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Van Erven, Dirk | .2002 |
| 'Christmas Cookies' | Med-Green | Medial | White | TC Sport | Pale-Lavender | July | Zilis, Mark | .2003 |
| 'Christmas Eve' | Dark-Green | Medial | White | Nat-Sport | - | June into July | Avent, Tony | .2010 |
| 'Christmas Island' | Med-Green | Medial | White | Unknown | - | - | Van Eechaute, Danny | --NR-- |
| 'Christmas Jewel' | Med-Green | Streaked | White | Hybrid | - | - | Malloy, Alex | --NR-- |
| 'Christmas Song' | Dark-Green | Marginal | White | Unknown | Med-Lavender | - | Heemskerk, Gerardus | --NR-- |
| 'Christmas Stockings' | Med-Green | Streaked | White | Hybrid | - | - | Malloy, Alex | --NR-- |
| 'Chromosphere' | Yellow | - | - | Hybrid | - | July into August | Zilis, Mark | .2010 |
| 'Chutzpah' | Med-Green | Streaked | White | Nat-Sport | Med-Lavender | July | Malloy, Alex | .2002 |
| 'Cinnamon and Sugar' | Med-Green | - | - | Unknown | - | - | Herold, Roy | --NR-- |
| 'Cinnamon Sticks' | Med-Green | - | - | Hybrid | Light-Purple | August to October | Herold, Roy & Walek, Kevin | .2009 |
| 'Cinnamon Twist' | Med-Green | - | - | Unknown | - | - | Herold, Roy | --NR-- |
| 'Circular Saw' | Med-Green | Marginal | Yellow | TC Sport | - | July into August | Zilis, Mark | .2009 |
| 'Cirrus Clouds' | Yellow | Streaked | White | TC Sport | Pale-Lavender | July into August | Anderson, Jim | --NR-- |
| 'Citation' | Med-Green | Marginal | Creamy White | Hybrid | Pale-Lavender | July into August | Aden, Paul | .1980 |
| 'City Dog' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | June into July | Van Eechaute, Danny | .2014 |
| 'City Slicker' | Dark-Green | Marginal | White | Hybrid | Deep-Purple | August to October | Dishon, Jim | .1996 |
| 'Clarence' | Blue/Green | - | - | Hybrid | Near-White | June into July | Simpers, Lucille | .1996 |
| 'Class Act' | Med-Green | Marginal | Yellow | Hybrid | Near-White | - | Zilis, Mark | --NR-- |
| 'Clattering Water' | Blue/Green | - | - | Nat-Sport | Med-Lavender | - | Fransen, Marco & Joyce | --NR-- |
| 'Claudia' | Med-Green | - | - | Hybrid | Light-Purple | July into August | Grenfell, Diana & Walek, Kevin | .2009 |
| 'Clean Green' | Light-Green | - | - | Hybrid | Pure-White | July into August | Goodenough, Rick & Gilligan, Madelon | .2017 |
| 'Clean Lines' | Med-Green | - | - | Unknown | Light-Purple | August | Livingston, Ron | --NR-- |
| 'Clean Shave' | Med-Green | Marginal | White | Nat-Sport | Med-Lavender | July into August | Lysne, Rod | .2019 |
| 'Clear Skies' | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Campbell-Bauer, Margaret | --NR-- |
| 'Clearfork Green' | Dark-Green | - | - | Unknown | Pale-Lavender | June into July | Wade, Van | .1999 |
| 'Clifford's Broken Heart' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | June into July | Clifford, John | .2000 |
| 'Clifford's Comet' | Dark-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Clifford, John | .2000 |
| 'Clifford's Stingray' | Dark-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Clifford, John & Ken | .2000 |
| 'Cloretta' | Med-Green | Medial | White | Unknown | - | - | Woods, Doyle | --NR-- |
| 'Cloud Lime' | Light-Green | - | - | Unknown | - | - | Serafin, Viktoria | --NR-- |
| 'Cloudburst' | Blue/Green | - | - | Hybrid | Light-Purple | July | Beilstein, Doug & Zilis, Mark | .2006 |
| 'Clouded Skies' | Blue/Green | - | - | Hybrid | Med-Lavender | July into August | Avent, Tony | .2007 |
| 'Clovelly' | Med-Green | - | - | Hybrid | Pale-Lavender | July | Terpening, Kent | .2005 |
| 'Clown Belly' | Blue/Green | Streaked | Yellow | Hybrid | - | - | Kuenster, Rod | --NR-- |
| 'Clyde Crockett' | Blue/Green | Marginal | Yellow | Hybrid | Near-White | August to October | Stygall, Patsy | .2007 |
| 'Coach Jim Fox' | Dark-Green | Streaked | White | Hybrid | - | July into August | Freeman, Franc | .2009 |
| 'Coach Millboy Miller' | Dark-Green | - | - | Unknown | - | July into August | Schwarz, Jim | .2015 |
| 'Coach Paul Castro' | Med-Green | Streaked | Yellow | Hybrid | - | August to September | Freeman, Franc | .2010 |
| 'Coal Black' | Dark-Green | - | - | Unknown | - | - | Schwarz, Jim | --NR-- |
| 'Coastal Treasure' | Med-Green | Marginal | Yellow | Hybrid | - | - | Desmedt, Rik | --NR-- |
| 'Cobra's Lair' | Blue/Green | - | - | Hybrid | - | - | Philips, Hugo | .2010 |
| 'Cogleywood' | Dark-Green | Medial | White | Unknown | Pale-Lavender | July | Shugart, Janet & Crowl, M & Hansen, L. | .1999 |
| 'Cojocabana' | Dark-Green | Streaked | Yellow | Unknown | - | July | Janssen, Bill | --NR-- |
| 'Colesburg Blue' | Blue/Green | - | - | Hybrid | Pale-Lavender | June | Hackbarth, Robert | .2004 |
| 'Colesburg Tyler John' | Med-Green | Streaked | White | Unknown | Light-Purple | July | Hackbarth, Robert | --NR-- |
| 'Colesburg Wiggles' | Med-Green | Marginal | Yellow | Unknown | Light-Purple | July into August | Hackbarth, Robert | .2015 |
| 'Colin P. Cleghorn' | Med-Green | Medial | White | Unknown | Pale-Lavender | July into August | Chamberlain, Steve | .2014 |
| 'Collector's Banner' | Yellow | Marginal | Green | Nat-Sport | Pale-Lavender | July | Janssen, Bill | --NR-- |
| 'Color a la Mode' | Dark-Green | Medial | White | Hybrid | Pale-Lavender | July | Elslager, Ed | .2000 |
| 'Color Accord' | Med-Green | Streaked | Speckles | Hybrid | Pale-Lavender | July | Aden, Paul | .1982 |
| 'Color Conundrum' | Blue/Green | Streaked | Yellow | Unknown | - | - | Unknown | --NR-- |
| 'Color Fantasy' | Blue/Green | Streaked | Speckles | Hybrid | Med-Lavender | August | Aden, Paul | .1980 |
| 'Color Festival' | Yellow | Marginal | Blue-Green | Nat-Sport | Med-Lavender | July | Van Eechaute, Danny & Heemskerk, Gerard | .2007 |
| 'Color Me Yellow' | - | - | - | Nat-Sport | - | - | Freeman, Franc & Sally | .2010 |
| 'Color Parade' | Light-Green | - | - | TC Sport | Pale-Lavender | August | Zilis, Mark | .2003 |
| 'Colored Cascade' | Blue/Green | Streaked | - | Nat-Sport | Deep-Purple | August to September | Unknown | --NR-- |
| 'Combined Elegance' | Yellow-Gold | - | | Hybrid | Pale-Lavender | July into August | Kwick, Charles | .2019 |
| 'Comeuppance' | Med-Green | - | - | Hybrid | Pure-White | July | Aden, Paul | .1982 |
| 'Commander Cody' | Blue/Green | Streaked | White | Unknown | - | - | Purvis, Owen & Sue | --NR-- |
| 'Community Chest' | Yellow | - | - | Hybrid | - | - | Malloy, Alex | --NR-- |
| 'Compadre' | Dark-Green | Medial | Yellow | Nat-Sport | Light-Purple | July into August | Ritchey, Allen | .2015 |
| 'Conflicted' | Med-Green | - | - | Unknown | Pale-Lavender | July into August | Kwick, Charles | .2017 |
| 'Confused' | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Beal, R. | .1999 |
| 'Connecticut River' | Blue/Green | - | - | Hybrid | Pale-Lavender | - | Beilstein, Doug & Malloy, Alex | .2005 |
| 'Considering Concordville' | - | - | - | Hybrid | Med-Lavender | - | Moore, Jeff | --NR-- |
| 'Constitution' | Dark-Green | Marginal | White | Hybrid | - | - | Goodenough, Rick | --NR-- |
| 'Continental' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | July | Malloy, Alex | --NR-- |
| 'Convivial' | Dark-Green | Marginal | White | Unknown | Near-White | - | Livingston, Ron | --NR-- |
| 'Cool Blue' | Blue/Green | - | - | Unknown | Med-Lavender | June into July | Benedict, Dr R. (Herb) & Kuenster, Rod | --NR-- |
| 'Cool Dreams' | Blue/Green | - | - | Hybrid | Pale-Lavender | June into July | Zilis, Mark | .2010 |
| 'Cool Hand Cam' | Dark-Green | - | - | Unknown | - | - | Schmidt, Bevie | --NR-- |
| 'Cool Waters' | Blue/Green | - | - | Hybrid | Light-Purple | June into July | Zilis, Mark | .2010 |
| 'Copa Cabana' | Yellow | - | - | Unknown | Light-Purple | July into August | Terpening, Kent | --NR-- |
| 'Coquette' | Med-Green | Marginal | Creamy White | Hybrid | Light-Purple | August | Benedict, Dr Ralph (Herb) | .1987 |
| 'Cordelia' | Blue/Green | Marginal | White | Hybrid | Deep-Purple | July into August | Kuk, Bob | .1991 |
| 'Corryvreckan' | Blue/Green | - | - | Unknown | - | - | Black, Gwen | --NR-- |
| 'Cosmic Blue' | Blue/Green | - | - | Hybrid | Med-Lavender | - | Livingston, Ron | --NR-- |
| 'Cosmic Eye Candy' | Med-Green | Streaked | Yellow | Hybrid | Pale-Lavender | June into July | Kuenster, Rod | .2014 |
| 'Cosmic Friendship' | Med-Green | Marginal | Yellow | Unknown | | | Kuenster, Rod | --NR-- |
| 'Cosmic Journey' | Dark-Green | Streaked | Speckles | Hybrid | Med-Lavender | June into July | Kuenster, Rod | .2010 |
| 'Cosmic Lady' | Med-Green | Streaked | White | Hybrid | - | June into July | Kuenster, Rod | .2010 |
| 'Cosmic Patchwork' | Med-Green | Streaked | Yellow | Hybrid | Near-White | June into July | Kuenster, Rod | .2014 |
| 'Cosmic Pistol' | Light-Green | Streaked | White | Hybrid | Near-White | July | Kuenster, Rod | .2012 |
| 'Cosmic Pluto' | Blue/Green | | | Unknown | | | Kuenster, Rod | --NR-- |
| 'Cosmic Rainbow' | Dark-Green | Streaked | Yellow | Hybrid | - | June into July | Kuenster, Rod | .2008 |
| 'Cosmic River' | Med-Green | Streaked | Yellow | Hybrid | Med-Lavender | July into August | Kuenster, Rod | .2011 |
| 'Cosmic Secret' | Blue/Green | Streaked | Yellow | Hybrid | Near-White | July into August | Kuenster, Rod | .2013 |
| 'Cosmic Sister' | Med-Green | Streaked | Speckles | Hybrid | Pure-White | June into July | Kuenster, Rod | .2006 |
| 'Cosmic Spotted Cow' | Med-Green | Streaked | White | Hybrid | Near-White | June into July | Kuenster, Rod | .2011 |
| 'Cosmic Warrior' | Med-Green | Streaked | Yellow | Hybrid | Pale-Lavender | June into July | Kuenster, Rod | .2014 |
| 'Cosmic Watercolors' | Med-Green | Streaked | Yellow | Hybrid | Near-White | July into August | Kuenster, Rod | .2011 |
| 'Cosmic Wings' | Blue/Green | Marginal | White | Unknown | - | - | Kuenster, Rod | --NR-- |
| 'Cosmic Wow' | Dark-Green | Medial | White | Unknown | - | - | Kuenster, Rod | --NR-- |
| 'Cotton Candy' | Med-Green | Streaked | Speckles | Nat-Sport | Med-Lavender | July into August | Zilis, Mark | .2009 |
| 'Count Dracula' | Dark-Green | - | - | Unknown | Pale-Lavender | August to September | Crockett, Clyde | .1997 |
| 'Count Your Blessings' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | July | Silvers, Bill | .2008 |
| 'Country Cousin' | Med-Green | Streaked | White | Hybrid | - | - | Ward, Dr Dick & Jane | .2012 |
| 'Country Double Take' | Med-Green | Marginal | Yellow | Hybrid | Med-Lavender | August to September | Dean, Don | .2019 |
| 'Country Rippled Relic' | Blue/Green | - | | Hybrid | Med-Lavender | July into August | Dean, Don | .2019 |
| 'Country Road' | Dark-Green | - | - | Hybrid | Pale-Lavender | July into August | Dean, Don | .2000 |
| 'Country Sun Drop' | Light-Green | - | - | Unknown | Light-Purple | July into August | Spece, Josh | --NR-- |
| 'Coventry' | Blue/Green | - | - | Unknown | - | - | Minks, Eldren | --NR-- |
| 'Cowrie' | Dark-Green | Marginal | Yellow | TC Sport | Pale-Lavender | July into August | Walters Gardens | --NR-- |
| 'Craig Harlequin Bells' | Dark-Green | - | - | Nat-Sport | Light-Purple | June into July | Craig, Jack & Ruh, Peter | .1999 |
| 'Crayola Kid' | Light-Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Barta, Jack | --NR-- |
| 'Crayons' | Med-Green | Streaked | White | Hybrid | Pale-Lavender | July | Seaver, Mildred | --NR-- |
| 'Crazy Hazy' | Blue/Green | Marginal | Yellow | Nat-Sport | Med-Lavender | - | Fransen, Marco & Joyce | --NR-- |
| 'Crazy Quilt' | Blue/Green | Streaked | White | Unknown | Near-White | July | Lachman, Wm & Eleanor | --NR-- |
| 'Crazy Spirit' | Med-Green | Streaked | Yellow | Nat-Sport | Pale-Lavender | August | Van Eechaute, Danny | --NR-- |
| 'Cream Delight' | Med-Green | Medial | White | Nat-Sport | Light-Purple | July | Ford, Richard & Mary | --NR-- |
| 'Cream Topping' | Blue/Green | Medial | White | Nat-Sport | Med-Lavender | - | Heemskerk, Gerardus | --NR-- |
| 'Creamsicle' | Light-Green | - | - | Unknown | - | - | Purvis, Owen & Sue | --NR-- |
| 'Creature from the Green Lagoon' | Med-Green | Marginal | Green | Nat-Sport | Pale-Lavender | July | Malloy, Alex | --NR-- |
| 'Creech' | - | - | - | Nat-Sport | - | - | Creech, John | --NR-- |
| 'Creek' | Blue/Green | - | - | Hybrid | Pure-White | June | Wade, Van | .2007 |
| 'Crème Brûlée' | Med-Green | Marginal | Yellow | Nat-Sport | Med-Lavender | July into August | Johnson, Greg | .2004 |
| 'Crème Solaire' | Yellow | - | - | Unknown | Near-White | June | Deckert, Emile & Jane | .2004 |
| 'Crescent Moon' | Blue/Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Walters Gardens | .1988 |
| 'Crested Surf' | Med-Green | Marginal | Creamy White | Hybrid | Light-Purple | August | Benedict, Dr Ralph (Herb) | .1990 |
| 'Crimson Desire' | Dark-Green | - | - | Hybrid | Med-Lavender | August | Dean, Don | .2017 |
| 'Crinkled Clink' | Dark-Green | - | - | Unknown | Med-Lavender | July | Livingston, Ron | --NR-- |
| 'Crocodile Smile' | Dark-Green | Medial | White | Unknown | Pale-Lavender | June into July | Kulpa, John | .2001 |
| 'Crocodile Socks' | Dark-Green | Marginal | Yellow | Nat-Sport | Pale-Lavender | June into July | van den Top, Jan | --NR-- |
| 'Crocodile Tears' | Dark-Green | - | - | Unknown | - | - | Meyer, Bill | --NR-- |
| 'Crossing the Rubicon' | Yellow | - | - | TC Sport | - | June into July | Zilis, Mark | .2009 |
| 'Crossroads Hurricane' | Blue/Green | Streaked | Yellow | Hybrid | Pale-Lavender | July into August | England, Tim | .2003 |
| 'Crossroads Parrot' | Med-Green | - | - | Hybrid | Pale-Lavender | July into August | England, Tim | .2003 |
| 'Crossroads Rowdy' | Med-Green | Marginal | White | Hybrid | Pale-Lavender | July into August | England, Tim | .2003 |
| 'Crossroads Whirlpool' | Blue/Green | Streaked | White | Hybrid | Pale-Lavender | July into August | England, Tim | .2003 |
| 'Crossview Can Can' | Med-Green | Medial | White | Nat-Sport | - | - | Cross, Leila & Harold | --NR-- |
| 'Crow' | Dark-Green | - | - | Unknown | - | - | Wade, Van | --NR-- |
| 'Crown Royalty' | Blue/Green | Marginal | Yellow | Hybrid | Pale-Lavender | July into August | Minks, Eldren | .1990 |
| 'Crowned Imperial' | Blue/Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Walters Gardens | .1988 |
| 'Crow's Feet' | Med-Green | - | - | Unknown | - | - | Pether, Glen | --NR-- |
| 'Crows Landing' | Med-Green | Marginal | White | Hybrid | Med-Lavender | June into July | Stygall, Patsy | --NR-- |
| 'Crows Landing Fairy Ghost' | Light-Green | - | - | Unknown | - | - | Stygall, Patsy | .2011 |
| 'Crows Landing Rippled Truffles' | Med-Green | Marginal | Yellow | Unknown | - | August to September | Stygall, Patsy | .2011 |
| 'Crows Landing Standout' | Blue/Green | Marginal | White | Unknown | - | July into August | Stygall, Patsy | .2011 |
| 'Crumples' | Med-Green | - | - | Hybrid | Pale-Lavender | July | Grenfell, Diana | .1996 |
| 'Crusader' | Dark-Green | Marginal | White | Hybrid | Pale-Lavender | August | Lachman, Wm & Eleanor | .1989 |
| 'Crusty Old Fart' | Dark-Green | - | - | Unknown | - | - | Freeman, Franc & Sally | .2010 |
| 'Cucumber Boat' | Dark-Green | - | - | Nat-Sport | Pale-Lavender | July | Reinermann, W. & Van Eechaute, Danny | --NR-- |
| 'Cumulonimbus' | Yellow-Gold | Marginal | White | Nat-Sport | Pale-Lavender | - | Roberts, Mark | --NR-- |
| 'Cup of Gold' | Yellow | - | - | Unknown | - | - | Wade, Van | --NR-- |
| 'Cup of Joy' | Yellow | - | - | Hybrid | Near-White | July | Myers, Gary | .2011 |
| 'Cupatini' | Med-Green | - | - | Hybrid | Near-White | August | Zilis, Mark | .2009 |
| 'Cupid's Dart' | Dark-Green | Marginal | White | Nat-Sport | Pale-Lavender | July | Walters Gardens | .1997 |
| 'Curious Yellow' (M. Seaver) | Yellow | - | | Unknown | | | Seaver, Mildred | --NR-- |
| 'Curls' | Med-Green | - | - | Hybrid | Pale-Lavender | July | Minks, Eldren | .1990 |
| 'Curly Fries' | Light-Green | - | - | Unknown | Deep-Purple | August | Solberg, Robert | .2008 |
| 'Curmudgeon' | Med-Green | - | - | Unknown | - | June into July | Brown, Sandy | .2010 |
| 'Curtain Call' | Blue/Green | - | - | Nat-Sport | Light-Purple | July into August | Wilkins, Dr Jim | .1998 |
| 'Curves' | Med-Green | Marginal | Yellow | Hybrid | Med-Lavender | July into August | Elslager, Ed | .2005 |
| 'Cutie' | Blue/Green | - | - | Unknown | Med-Lavender | August to October | Benedict, Dr R. (Herb) & Kuenster, Rod | .2010 |
| 'Cuyahoga' | Med-Green | Marginal | Yellow | Hybrid | - | July into August | Zilis, Mark | .2009 |
| 'Cuyahoga Falls' | Dark-Green | - | - | Nat-Sport | - | July into August | Zilis, Mark | .2010 |
| 'Cyclone' | Dark-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Schwarz, Jim | .2002 |
| 'Cyclone Wrestling' | Dark-Green | - | - | Unknown | - | July into August | Freeman, Franc | .2011 |
| 'Czech It Out' | Blue/Green | Marginal | White | Nat-Sport | Pale-Lavender | June | Van Wyke, Trudy | --NR-- |
|