505 ILCS 90/11
It shall be unlawful for any person to bring or cause to be brought into this State any nursery stock unless there is plainly and legibly marked thereon or affixed thereto, or on, or to the car or other vehicles carrying the same, or on the bundle, package, or other container of the same in a conspicuous place, a statement showing the names and addresses of the consignor, and the consignee, the general nature of the contents, together with a certificate of inspection of the proper official of the state, territory, district, or country from which it was brought or shipped, showing that such nursery stock was found or believed to be free from insect pests and plant diseases. For Christmas trees originating outside Illinois only trees from State or federal quarantine areas are required to be accompanied by a certificate of inspection.
505 ILCS 90/11