Roi des Rouges requires research.
Roongkarn requires research.
Canna 'Rosa Feurta' is a medium-sized Crozy Group cultivar, with green leaves and pink flowers.
Rose Morn requires research.
Rose of May requires research.
Rose Queen requires research.
Rose Supreme requires research.
Rose Unique requires research.
Rosea Superba requires research.
Rotundifolia major requires research.
Rotundifolia metallica requires research.
Rotundifolia rubra requires research.
Rotundifolia rubra major requires research.
Rotundifolia vera requires research.
Rubricaulis requires research.
S. Milland requires research.
S.T. Wright requires research.