Ranunculus isthmicus 
Ranunculus macrorhynchus 
Ranunculus millefolius 
Ranunculus myosuroides 
Ranunculus paludosus 
Ranunculus pinardii 
Ranunculus saniculifolius 
Ranunculus scandicinus 
Ranunculus tenuilobus 
Ranunculus uncinatus 
Red Baneberry 
Red-Horned Poppy 
Rhaetian Alpine Poppy 
Rockslide Larkspur 
Roemeria hybrida 
Roemeria refracta 
Rough-fruited buttercup 
Rue Anemone 
Sad poppy 
Sagebrush buttercup 
Scarlet Pheasant's Eye 
Scouler's Corydalis 
Sea oxeye daisy 
Semitic Poppy