BigXthaPlug — one of rap’s biggest rising stars — has been arrested on a marijuana charge in Texas … TMZ has learned.

BigX was arrested on Wednesday and is currently being held at the Arlington City Jail. He’s been charged with possession of less than 2 ounces of marijuana.

Arlington PD tells TMZ … around 12:05 AM local time, BigX was driving with expired tags and got pulled over by cops. The officer reported he could smell marijuana as he approached the vehicle and asked BigX and the passenger — Cleodist Landum — to exit the car.

Officers said they could see cigarettes and a green leafy substance in the console of the vehicle … and said they also located a handgun in the passenger door pocket.

22-year-old Cleodist — who appears to be BigX’s relative — had an active felony warrant out of Bexar County, Texas. When officers took him into custody and searched him, they allegedly found marijuana on him. He was booked into the Arlington City Jail on the warrant, as well as for possession of marijuana, and unlawful carrying of a weapon.

The rapper’s a proud Texas native, born in Dallas, not far from Arlington.