Black Orchid And The Rubaiyat

By rereading Neil Gaiman's and Dave McKean's Black Orchid, Book One, I have learned Quatrain 26 of the Rubaiyat of Omar Khayyam:

"Oh, come with old Khayyam and leave the Wise
"To talk; one thing is certain, that Life flies;
"One thing is certain, and the Rest is Lies;
"The flower that once has blown forever dies."

Why does he say "blown"?

Wiki tells me that "Rubaiyat" means "quatrains."