Plagiobothrys arizonicus 
Pride of Madeira 
Pulmonaria obscura 
Purple Gromwell 
Purple Viper's-bugloss 
Rindera lanata 
Rochelia disperma 
Russian Comfrey 
Rusty popcornflower 
Scouler's popcornflower 
Sea Lavender 
Seaside heliotrope 
Shrubby Gromwell 
Siberian Bugloss 
Silky Phacelia 
Siricote 
Sitka mistmaiden 
Small bluebells 
Small Bugloss 
Small-flowered Forget-Me-Not 
Smooth Honeywort 
Snake River Cat's-eye 
Solenanthus circinnatus 
Spreading Stickseed