Ding dong, the witch is dead.
Considering that poppy flowers are generally symbols of sleep, death, remembrance after death, etc, it’s rather fitting in its role in The Wizard of Oz. There are a few legends surrounding poppies. My favorite is the Greek one that connects it to Morpheus, the god of dreams. Apparently, the cave where he sleeps is filled with poppy seeds and they bloom as he slumbers. That would have been a pretty good visual for a spread in Sandman.
Also, they’re pretty.