Famous Wizard cards and film spells

Q: Did you actually write the information that ended up on the Famous Wizard cards? For that matter, what about the spells in the films? Did you invent those or did Steve Kloves? And why were new incantations created for the movie in the first place? (Example: “Incendio” to “Lacarnum Inflamari”?
A: Yes, I wrote the information on the original Famous Wizard cards. As you have noticed, a few of them have now popped up on the ‘Wizard of the Month’ cards on my website desk.

Spells in the films – there I’ve lost track. Steve invented some and I gave him others. Some of the new incantations, such as “lacarnum inflamari” must have sounded more dramatic onscreen – although by the time you’ve managed to say “lacarnum inflamari”, you’ve surely lost precious moments in which the Devil’s Snare might have throttled you. But that’s showbiz.
— Jo Rowling