Eon Rose

The Eon Rose is a magical flower. It has five petals of different hues; fiery red, emerald green, snowy silver, deep-sea blue and midnight black; surrounding a golden sphere in the center. Krasus used this flower along with a spell to transport himself to Nozdormu's home.

Speculation
The flower may only grow in the Caverns of Time, or at least specifically in Nozdormu's lair.