Midworld is a fictional planet created by Alan Dean Foster for his Humanx Commonwealth universe. Its distinguishing feature is the thousand meter high rainforest that covers nearly all of the planet, making it the most biologically diverse planet in the universe. It is home to a human offshoot known as Midworlders who are slightly smaller than human standard with adaptations that include light green skin and long toes.
The planet is currently under edict—all travel to the planet is expressly forbidden—by the United Church, ostensibly to protect the fragile ecosystem. More likely it is to protect the Commonwealth from the emerging world-consciousness that the massive rainforest has spawned. Bits of this plant-based sentience have been placed upon Flinx’s ship Teacher allowing the planet-consciousness to now travel the universe.