Moon flower

A moon flower is a plant that exists in the Smurf Forest.

Mainstream Smurfs Media
This plant appeared in the beginning of "I Was A Brainy Weresmurf" when Brainy Smurf is knocked into it by a wolf cub. The flower's sap enters his open scratch, which ends up turning him into a Weresmurf, as documented in one of Papa Smurf's books.