The New Hampshire Invasive Species Committee, part of the Department of Environmental Services , came out with a list of proposed prohibited and restricted invasive plant and insect species for the state. Created this past July, the list is full of well-known baddies, many of them already banned in NH since thelate 1990s. The New Hampshire Watershed Bureau web site has lots of other information about non-native plant species.
(Thanks to a member of the Yahoo! newsgroup ma-eppc for posting info about this topic.)