A weed is simply an unwanted plant, but a noxious weed is a dangerous thug. On this week's Weekend Edition Saturday, Ketzel and Scott talk about a couple of plants that are so bad, they've been banned.

The haunting spectre of kudzu Photo by Jack Anthony

Weeds Gone Wild: Alien Plant Invaders of Natural Areas is a fabulously useful and user-friendly Web site maintained by the Plant Conservation Alliance. Not only can you access easy-to-read lists of invasive, non-native plants, you can also find each plant's mug shot and rap sheet, complete with recommendations for plant eradication and/or control.

The USDA's list of regulated noxious weeds is the motherlode of Most Unwanted. The plants are arranged alphabetically by their scientific names, so you might not find it helpful if you don't speak botanic Latin. If you're curious about what plants are considered noxious in your own state, try the following link:

The National Plant Board's map of the USA offers instant access to each state's Division of Agriculture website. Once there, you can find out what plants have been banned and/or quarantined in your own backyard.

The Federal Interagency Committee for the Management of Noxious and Exotic Weeds offers an information-heavy briefing about invasive plants. The site also contains an online version of the Fed's Weed Fact Book.

A kudzu-encrusted cabin Photo by Jack Anthony

Jack Anthony's photos of landscapes smothered in kudzu will tell you all you need to know about this scary vine. His Web site is one of the highlights of an online kudzu cult, and offers links to other similarly-obsessed members.

Invasive Plants: Weeds of the Global Garden is one of the Brooklyn Botanic Garden's series of immensely reliable and likeable booklets on plants and gardens. This particular publication is a solid bet for the beginner who is ready to dig in. To get thoroughly hooked, read Janet Marinelli's wonderful Introduction.