Purple Loosestrife Infestation (Lythrum salicaria L.) Photo: Agriculture and Agri-Food Canada Archive, Agriculture and Agri-Food Canada, Bugwood.org
It is a violation of law to sell or transport certain plants as determined by federal and state governments. The list of these plants is subject to change and should be accessed directly from the USDA's website. Always be wary of using any plant on a noxious weed list in another state. It is very likely to become a listed problem plant where you are located in the future.
Federal Noxious Weed List
"No person may move a Federal noxious weed into or through the United States, or interstate, without a federal permit." See Title 7, Section 360 Code of Federal Regulations for more information (7 CFR 360).
Pennsylvania Noxious Weed List
"When a weed is declared noxious it shall be a violation of this act to sell, transport, plant, or otherwise propagate that weed within the Commonwealth, except that the secretary may permit exceptions for specific horticultural or experimental use."
This information was generated through a collaboration between Penn State Extension and the Mid-Atlantic Panel on Aquatic Invasive Species.