Snowberry          

Snowflake          

Soapberry          

Soapweed Yucca      

Soapwort          

Soft Agrimony          

Soft Brome          

Soft Fox Sedge          

Soft Goldenaster          

Soft Thistle          

Soft-hair Marbleseed          

Softhair Marbleseed          

Softleaf Arrowwood          

Softleaf Blackberry          

Softleaf Rosette Grass          

Softstem Bulrush      

Sorghum      

Sorrelvine          

Soulard Crab          

Sour Cherry          

South American Mock Vervain          

Southeastern Wildrye          

Southern Adderstongue          

Southern Annual Saltmarsh Aster          

Southern Arrowwood          

Southern Blue Monkshood          

Southern Catalpa      

Southern Cattail          

Southern Crab Apple          

Southern Crabgrass          

Southern Dewberry          

Southern Jointweed          

Southern Prairie Aster          

Southern Red Oak      

Southern Sedge          

Southern Spicebush          

Southern Sugar Maple      

Southern Waternymph      

Southwestern Bedstraw          

Southwestern Cosmos          

Sowthistle          

Soybean      

Spanish Gold          

Spanish Needles