I didn’t get this at all, but urban dictionary tells me it’s from the 1946 movie It’s a Wonderful Life.

A phrase from the 1946 movie “Its a Wonderful Life”. The petals belong to Zuzu Bailey, the youngest daughter of George Bailey the main character. Zuzu had brought a flower home from school. When she was upset that a few petals had fallen off, George pretended to reattach them and secretly slipped them into his pocket.

Towards the end of the movie, after being shown what the world might be like if he had never been born, George is given a second chance by God. Changes that had occurred while he didn’t exist, were returned. He is initially made aware of this, in part, by the fact that Zuzu’s Petals were again in his pocket.
“Zuzu’s petals…Zuzu… There they are!”

As an aside, the username that created that entry in 2009? ZuzusPetals.