The D.A. in Coweta County slapped the Louisiana rapper with possession of less than an ounce of marijuana, and possession of a controlled substance. When you see it's less than an ounce of weed, ya might think it's not that serious, but Georgia ain't Colorado or California -- it still takes marijuana very seriously.

As we reported, Boosie was arrested back in April when cops pulled him over in his white Dodge Charger for swerving lanes and nearly hitting another vehicle. During the traffic stop, officers found the ganja, one handgun and more than $20,000 in cash.

Prosecutors decided not to charge Boosie for the gun possession.

It's unclear why he got the pass. Boosie did have a passenger in the car, who is also facing the same 2 drug charges. If convicted, both men are looking at least 1 year in prison ... depending on how many grams of green they had. Remember, Boosie previously did 5 years in Louisiana for drug charges.

One last piece of accounting in the case -- prosecutors tacked on a traffic violation for Boosie ... failure maintain his lane.