The first one is Aphrodite, the goddess of love ("Venus" is her name in Roman mythology, which has another name for roses). When she rose from the sea, her foam turned into a white rose, dyed red with the blood of her lover adonis. It should be the version said by the students on the first floor, with slightly different details.
The second version spread more widely: Chloris, the goddess of flowers, turned the body of the dead goddess into a rose, Aphrodite named her and endowed her with beauty, Dionysus, the goddess of wine, endowed her with fragrance, graced her with charm, and other gods also helped, so the rose was born and was called the queen of flowers.
The version of Roman mythology is that there was a beautiful woman named Rodens who was very beautiful. Tired of many suitors, she hid in the temple of Diana, the virgin goddess, and sought refuge. But after a long time, Diana began to envy the beauty of Rodin, so when her suitors rushed into the temple, she turned Rodin into a rose and her suitors into thorns.