Scottish primrose 
Sea Milkwort 
Sea Primrose 
Sheep-laurel 
Shinleaf 
Shooting star 
Showy Phlox 
Shy gilia 
Siebold's Primrose 
Slender phlox 
Slenderleaf collomia 
Small Balsam 
Small Cranberry 
Small-leafed White Beard 
Snow Douglasii 
Snow Dwarf Primrose 
Snow Plant 
Snow Wreath 
Snowdrop Bush 
Snowline wintergreen 
Sourwood 
Sparkleberry 
Spotted Wintergreen 
Spreading phlox