Two Creekside Elementary School students helping a bus driver clean the bus on Tuesday morning did a good deed when they found and turned in a bag full of a green, leafy substance.

Under adult examination, however, the substance turned out to a different “herb” from what the kids thought they had found.

The students found the plastic sandwich bag between the seat cushions in a seat toward the rear of the bus. The driver turned it in to the assistant principal at the school, who called police, city spokeswoman Diana Klink wrote in an email.

However, the officer said the substance did not look or smell like marijuana. A field test kit confirmed the substance was not marijuana.

“Officer noted that the substance smelled similar to oregano, a green leafy herb used in cooking,” Klink wrote.

The officer took the bag into his possession so it could be destroyed.

The bus where the bag was found is used to transport both Creekside Elementary School and John Yeates Middle School students, Klink said. Police do not know when the bag could have been left on the bus.