CSSA - Cactus and Succulent Society of America, Inc
TACSS - Texas Association of Cactus and Succulent Societies
CDRI - Chihuahuan Desert Research Institute, in Fort Davis, Texas. Info about deserts, the Institute, their Nature Center, and special events
ACCS Austin Cactus & Succulent Society
NTCSS North Texas Cactus & Succulent Society, in Dallas
SACXS San Antonio Cactus and Xerophyte Society
TCSS Tucson Cactus & Succulent Society. Be sure to visit their Cactus Rescue page.
COCSS The Central Oklahoma Cactus and Succulent Society
FORT WORTH CACTUS AND SUCCULENT SOCIETY
Miles2Go - outstanding source of mail order plants
CactiGuide - A wealth of info about cacti. You can search by scientific name or common name, geographic distribution, or growth habit. There's also a terminology page, forums, advice on growing cacti, pests & disease, and other articles.
RARE AND UNUSUAL - JUST FUN STUFF
Desert Tropicals - good identification resource with pictures of specimens
The Natural Gardener in Austin - Great resource site and place
Dave's Garden - Plant info, bug info, reference sources, a variety of gardening forums, and more.
Cactus and Succulent Plant Mall. Tons of useful links to plant data, gardening info, cactus clubs, and events.
Cultivar - A fabulous online magazine devoted to crested, monstrose, and other freaky forms of succulents.
Peckerwood Garden - in Hempstead, Texas: rare and unusual plants from the United States, Mexico, and Asia.
Boyce Thompson Arboretum - in Superior, Arizona: a huge educational collection of desert plants.
Irwin Lightstone - Website of the excellent photographer we met at our February 2009 meeting.