Rush pussytoes 
Rush Skeletonweed 
Russian knapweed 
Sagebrush false dandelion 
Sand Sagebrush 
Santa Barbara Daisy 
Santa Maria Feverfew 
Sanvitalia procumbens 
Saw-tooth Sage 
Saw-Wort 
Scabland sagebrush 
Scentless False Mayweed 
Scorzonera alpigena 
Scorzonera eriophora 
Scorzonera libanotica 
Scorzonera meyeri 
Scorzonera mollis 
Scorzonera multiscapa 
Scorzonera papposa 
Scorzonera phaeopappa 
Scorzonera psychrophila 
Scorzonera rigida 
Scorzonera schweinfurthii 
Scorzonera syriaca