| Date |
Flower |
Family |
Scientific Name |
Photo |
Caption |
| 2008-03-01 | Chicory, Desert | - Sunflower Family | Rafinesquia neomexicana |  | Brown Mountain Trail, Tucson Mountain Park - - - March 1, 2008 |
| 2001-08-17 | Chokecherry | | Prunus virginiana |  | Clear Lake Ridge Preserve - - - August 17, 2001 |
| 2023-09-01 | Chokecherry | Rose Family | Prunus virginiana |  | Inspiration Garden - Independence, Oregon - Sep 1, 2023 |
| 2002-07-03 | Clarkia, Elkhorns | - Evening Primrose Family | Clarkia pulchella |  | North Fork John Day Wilderness - - - July 3, 2002 |
| 2007-06-20 | Clarkia, Tongue | - Evening Primrose Family | Clarkia rhomboidea |  | East Metolius River Trail, Deschutes National Forest - - - June 20, 2007 |
| 2002-06-20 | Cliff Douglasia | - Primrose Family | Douglasia laevigata |  | Cone Peak, Willamette National Forest - - - June 20, 2002 |
| 2003-04-12 | Clover, Bigheaded | - Pea Family | Trifolium macrocephalum |  | Memaloose Hills, Columbia Gorge National Scenic Area |
| 2007-07-03 | Clover, Marsh | - Pea Family | Trifolium wormskioldii |  | Lagoon Loop Trail, Oregon Dunes National Recreation Area - July 3, 2007 |
| 2001-07-21 | Clover, Owl | - Figwort Family | Orthocarpus imbricatus |  | Iron Mountain, Willamette National Forest - - - July 21, 2001 |
| 2007-06-18 | Collomia, Grand | - Phlox Family | Collomia grandiflora |  | East Metolius River Trail----June 18, 2007 |
| 2001-07-21 | Columbine | - Buttercup Family | Aquilegia formosa |  | Iron Mountain, Willamette National Forest - - - July 21, 2001 |
| 2009-07-28 | Common Touch-Me-Not | | Impatiens noli-tangere |  | Spencer Creek Nature Trail, Beverly Beach State Park - - July 28, 2009 |
| 2002-07-04 | Coneflower | - Sunflower Family | Rubeckia accidentalis |  | North Fork John Day Wilderness - - - July 4, 2002 |
| 2005-06-29 | Coral Root, Spotted | - Orchid Family | Corallarhiza maculata |  | Crescent Mountain, Willamette National Forest - - - June 25, 2005 |
| 2003-05-13 | Coral Root, Striped | - Orchid Family | Corallorhiza striata |  | Wygant Trail, Columbia Gorge National Senic Area - - - May 13, 2003 |
| 2005-04-18 | Corydilas, Scouler's | - Bleeding Heart Family | Corydilas scouleri |  | Silver Falls State Park - - - April 18, 2005 |
| 2009-08-30 | Crabapple | - Rose Family | Malus fusca |  | Silver Falls State Park - - - August 30, 2009 |
| 2010-03-21 | Cream Cups | Poppy Family | Platystemon californicus |  | Catalina State Park, Arizona - - - - March 21, 2010 |
| 2010-01-17 | Creosote Bush | - Caltrop Family | Larea tridentata |  | Buckskin Mountain State Park, Arizona - - - - January 18, 2010 |
| 2003-05-09 | Cucumber, Wild | Cucumber Family | Marah oreganus |  | Catherine Creek, Columbia Gorge National Scenic Area - - May 9, 2003 |
