Edenoi was the home of Dex, the Masked Rider, and the planet where King Lexian built Alpha 5 (and presumably the other Alpha units).
It is unknown what Edenoi looked like before the invasion of Count Dregon. During his occupation, it was a barren wasteland, rocks and desert and pockets of poisonous gas that the inhabitants were forced to mine. It has at least two satellites.
Edenoi acted as home to at least two species. The Edenoites were descended from insects, but appeared almost fully human, except for a round iridescent gem in the middle of the forehead through which they channeled most of their telepathic abilities. The second species were the Anitro, a collection of humanoid-animal crossbreeds.
It was conquered by Count Dregon some time before 1995, when the Mighty Morphin' Power Rangers (sans Kimberly) came to make sure everything was all right. They briefly allied with Dex and his friends before returning to Earth. Dex later left for Earth as well, given the Masked Rider powers by his grandfather before departing.
Although the later history of Edenoi is unknown, it can be assumed that the Z-Wave wiped out Count Dregon and his Plague Patrol, freeing the Edenoites. An S.P.D. outpost was established some time later.
By the year 2125, Dex had become Edenoi's king.