**FILE** A bar code is seen attached to a marijuana plant at a grow house in Denver on Jan. 26, 2013. The bar codes are assigned to each plant and follow it through the growing and distribution process. (Associated Press)

Photo by: Ed Andrieski

**FILE** A bar code is seen attached to a marijuana plant at a grow house in Denver on Jan. 26, 2013. The bar codes are assigned to each plant and follow it through the growing and distribution process. (Associated Press)