Petalburg Gym (from Norman after scanning the Ginema Berry e-Reader card; repeatable if the card is scanned again and the player has no e-Reader Berries in the Bag or PC when talking to him) Transformation from a different e-Reader Berry after scanning the Ginema Berry e-Reader card
The White Herb, also introduced in Generation III, has a similar effect to the Ginema Berry - but is unaffected by Berry-affecting moves and abilities, such as Pluck and Unnerve. As a result, the Ginema Berry was already largely redundant when it was introduced.
Origin
The Ginema Berry's design and name may be based on a タマネギ (Tamanegi) (onion).