| Date |
Flower |
Family |
Scientific Name |
Photo |
Caption |
| 2001-07-10 | Sunflower, Wooly | - Sunflower Family | Eriophyllum lanatum |  | Mt Elijah, Siskiyou National Forest - - - July 10, 2001 |
| 2005-03-28 | Sunflower, Desert | - Sunflower Family | Geraea canescens |  | Salton Sea, Colorado Desert - - - March 15, 2005 |
| 2003-06-05 | Strawberry, Woodland | - Rose Family | Fragaria vesca |  | Wenaha-Tuccanon Wilderness - - - June 5, 2003 |
| 2001-05-17 | Strawberry, Wild | - Rose Family | Fragaria viginiana |  | Metolius River, Deschutes National Forest - - - May 17, 2001 |
| 2009-04-19 | Strawberry, Coastal | - Rose Family | Fragaria chiloensis |  | Tahkenitch Dunes - - - April 19, 2009 |
| 2003-04-15 | Stoneseed | - Borage Family | Lithospermum ruderale |  | Cherry Orchard Trail, Columbia Gorge National Scenic Area - - - April 15, 2003 |
| 2007-06-08 | Stonecrop, Spreading | - Stonecrop Family | Sedum divergens |  | Illahee Lookout Trail - June 8, 2007 |
| 2001-07-21 | Stonecrop, Oregon | - Stonecrop Family | Sedum oregonense |  | Iron Mountain, Willamette National Forest - - July 21, 2001 |
| 2002-05-18 | Starflower | - Primrose Family | Trientalis latifolia |  | French Pete Creek Trail - - - May 18, 2002 |
| 2002-08-30 | St. John's Wort, Western | - St John's Wort Family | Hypericum formosum |  | Eagle Cap Wilderness - - - August 30, 2002 |
| 2002-08-03 | St. John's Wort, Common | - St. John's Wort Family | Hypericum perforatum |  | Iron Mountain, Willamette National Forest - - - August 2, 2002 |
| 2002-06-20 | Springbeauty | - Purslane Family | Claytonia lanceolata |  | Cone Peak, Willamette National Forest - - - June 20, 2002 |
| 2004-03-13 | Spring Witlow-grass | - Mustard Family | Darba verna |  | Lyle Cherry Orchard Trail - - - March 13, 2004 |
| 2002-05-30 | Spring Queen | - Figwort Family | Synthyris reniformis |  | Marys Peak - - - May 30, 2002 |
| 2009-07-03 | Spirea | - Rose Family | Spiraea douglasii |  | Tenmile Lake, Oregon Coast - - July 3, 2009 |
| 2002-05-30 | Sorrel | - Oxalis Family | Oxalis oregana |  | Marys Peak - - - May 30, 2002 |
| 2002-05-05 | Solomon's Seal, Star-flowered | - Lily Family | Smilacina stellata |  | Woodscape Nature Preserve - - - May 5, 2002 |
| 2002-06-14 | Solomon's Seal, False | - Lily Family | Smilacina racemosa |  | Marys Peak - - - June 14, 2002 |
| 2003-09-02 | Snowberry, Mountain | - Honeysuckle Family | Symphoricarpos oreophilus |  | Black Butte, Deschutes National Forest - - - September 2, 2003 |
| 2009-07-12 | Snowberry, Common | | Symphoricarpos albus |  | Metolius River Trail - - - - - September 26, 2005 |
