Flower Gift raises all party Pokémon's Attack and Special Defense stats by 50% in sunshine. Cherrim, the only Pokémon to have this Ability, also changes forms in sunlight, from a closed flower (Overcast Form) to one with spread petals (Sunshine Form); however, this is not caused by Flower Gift in Generation IV.
Bulbapedia. :D
http://bulbapedia.bulbagarden.net/wiki/Flower_Gift_(Ability)
