Petit/Petty Misdemeanor?

I’ve seen petit/petty misdemeanor written both ways and I was wondering which is correct (or are they both correct?)

American Heritage Dictionary defines as:

pet·it also pet·ty adj. Law. Lesser; minor. [Middle English, from Old French.]

I think “petty” is by far the more common modern spelling, although if you used “petit” most would know what you meant. The one exception is when referring to a jury, which is technically a petit jury, but nobody uses that phrase except in order to contrast it with a grand jury.

–Cliffy

The Florida Statutes use the French spelling in the case of petit theft, IIRC.