The World's Fairest Rose

There was once a queen who possessed a magnificent garden, filled with many varied flowers. One day, she fell ill and her doctors had little hope of a recovery. Only one of them said that a cure existed: the loveliest rose in the world. If it was found and brought to the queen, she would be saved. But where was the loveliest rose? And what was she called? No one knew, but they went looking.