Rosa canina, commonly known as the dog rose, was already being cultivated by the Romans, not so much for its flowers as for its fruit - the rose hips - which were thought to cure the bite of a mad dog. Unlikely. But it is true that this rose's hips are unusually high in antioxidants and it was used for a variety of medical purposes over  the centuries. Even in the 40's, it appeared in you WW II victory gardens as a source of Vitamin C when fresh produce was scarce. Its single pink flowers have also played a role in history. They're the basis for the rose used in European heraldry. And Shakespeare referred to it in A Midsummer's Night Dream.