What does Flower Head precisely do?

[RBYGSCRSFRLGEPD]

Cherrim's ability. Every site I've read said "it raises stats..." vaguely. I want to know what it precisely does--like, is it by one level? Every stat? Does it change its base stats? And so on.

 

[Jukain]

I don't know about the stat gain, but it does something else as well. When Sunny Day is in effect, Cherimu goes from this

to this

 

[mikarugelord]

I think it raises Special Attack. Handy for an aiding exxegutor or Groudon.

 

[Nando]

Doesn't the boost apply to both Pokémon (Cherrim and its partner) in a double battle? I seem to recall someone commenting that Mysterio's Groudon team in PBR---which has a Cherrim---could produce horrifically strong Sacred Fire attacks if his Ho-oh was out with Cherrim and the sun was in effect.