Flowers of the cranium were actually flowers which sprouted from infant skull sprouts. Kaat Thrick-Thrick, an expert in horticultural education, focused her studies on these unique plants.
The existence of cranial flowers was first brought to light in Monsters and Aliens from George Lucas, a book that hit shelves in 1993. Leland Chee, a worker at Lucasfilm responsible for the Holocron continuity database, has stated that the details presented in the aforementioned book are considered non-canonical.