Yay anime! Utena is a pretty unique anime in which roses are used pretty heavily. Roses are used as a motif for not only the shows central theme, love and the blossoming of new love. But as a metaphor to life. Something frail that requires constant care, but can be beautiful. The Rose Bride, a central figure to the story, is also both a source of great power but also great pain. Within her she hold the ‘sword of dios’, or blade of god, and will grant one of the characters the power to ‘revolutionize the world.’
Roses are unique in that they are one of the few flowers associated with the ability to hurt you, other flowers do have thorns, but those thorns are less relevant than. It’s discovered late in the series that the rose bride is actually a source of evil essential, and also trapped in eternal pain.
Rose are also used to accentuate nearly everything in utena, from the addition of a new character, to being used instead of speed lines when utena plays sports. This is almost comedic as opposed to motif, but does aide the idea roses are life in the context of the anime.