We are told that the rose is incredibly important to Dr. Heidegger, as it was given to him by Sylvia Ward to be worn on their wedding day before her unfortunate death. However, it is also vitally important to the short story, as Hawthorne uses it symbolically to reinforce the message of this tale. When Dr. Heidegger throws the rose into the water from the Fountain of Youth, it blooms once more:
Soon, however, a singular change began to be visible. The crushed and dried petals stirred, and assumed a deepening tinge of crimson, as if the flower were reviving from a deathlike slumber; the slender stalk and twigs of foliage became green; and there was the rose of half a century, looking as fresh as when Sylvia Ward had first given it to her lover.
Of course, this symbolises the change that is about to occur in each of the guests as they drink the Water of Youth, and it also indicates the reversal in their youth at the end. When it does fade once more, intriguingly, Dr. Heidegger says about it:
"I love it as well thus, as in its dewy freshness."
Clearly, Dr. Heidegger is pointing towards the moral of this story - ageing brings its own benefits, such as reflection and wisdom, which are just as important and valuable as the youth that his guests are so eager to re-live and waste once more.