The mysterious seeds that have turned up in mailboxes across the United States have been identified.
According to the U.S. Department of Agriculture, a number of the packets -- which appeared to have originated in China -- contain mixtures of mustard, cabbage and morning glory seeds, while others contain a mix of mint, sage, rosemary and lavender seeds. The news comes after state officials warned residents against planting the seeds, fearing they were sent as part of a plan to introduce invasive plants to the U.S.
USDA officials believe the seeds were actually sent out as part of a "brushing scam," which involves sending unsolicited samples of a product to someone and then posting a bogus positive review from the receiver.