opened up a sealed bag of potting soil and found a plant growing in it?

Madge was wanting to pot up some plants and was digging soil from my garden. I told her that I had two large bags of potting soil that had not even been opened. When I opened the bag I found the plant that is in the center and toward the top of the picture. Madge said to plant it in her planter and see what it will do. I expect it will die going from a plastic bag to near full sun.

One bag was bought last year, the other was bough early this year. The place I buy the potting soil mixes up their own mixture and I expect they got one of their seeds in it.

Larry