Some people seem to classify all desert plants as "cactus" but that is not at all correct. Cactus are one kind of very specialized plant. The general category of plants that are adapted to harsh, dry conditions are succulents, that is, plants that store some of their water in their leaves or other modified plant parts. I found these particularly interesting succulents at the Thanksgiving Point Garden, far from a traditional desert looking setting. Not all succulents are suited for hot, dry climates. Some require much cooler weather. There are about 60 different plant families that contain succulents. Here are some resources for finding out about these amazing plants:
Andersohn, Günter. Cacti and Succulents. East Ardsley, Wakefield, England; New York, N.Y.: EP Pub. ; Distributed by Sterling Pub. Co., 1983.
Baldwin, Debra Lee. Designing with Succulents. Portland, Or.: Timber Press, 2007.
Cutak, Ladislaus. Succulents. [St. Louis], 1959.
Hall, H. Common Succulents. London; New York: Longmans, Green, 1955.
Hecht, Hans. Cacti & Succulents. New York: Sterling Pub. Co., 1994.
Hewitt, Terry. Cacti & Succulents. New York, NY: DK Pub., 1996.
———. Succulents. London: Southwater, 2002.
———. The Complete Book of Cacti & Succulents. London; New York; Boston: Dorling Kindersley ; Distributed by Houghton Mifflin, 1993.
Hewitt, Terry, and Royal Horticultural Society (Great Britain). Garden Succulents. London: Cassell Illustrated : The Royal Horticultural Society, 2003.
Innes, Clive. Succulents. London; New York, N.Y.: Cassell : Royal Horticultural Society ; Distributed by Sterling Pub. Co., 1989.
Kelaidis, Gwen Moore, and Saxon Holt. Hardy Succulents: Tough Plants for Every Climate. North Adams, MA: Storey Pub., 2008.
Kramer, Jack. Cacti and Other Succulents. New York: Abrams, 1977.
———. Succulents and Cactus. Menlo Park, Calif.: Lane Books, 1970.
Lamb, Edgar, and Brian Michael Lamb. The Illustrated Reference on Cacti & Other Succulents. London: Blandford Press, 1955.
Loves, June. Succulents. Philadelphia: Chelsea Club House, 2005.
Perl, Philip, Enrico Ferorelli, and Time-Life Books. Cacti and Succulents. Alexandria, Va.: Time-Life Books, 1978.
Rowley, Gordon D. Flowering Succulents. Farnham, Surrey: Living Colour Publications, 1959.
———. The Illustrated Encyclopedia of Succulents. New York: Crown Publishers, 1978.
Sajeva, Maurizio, and Mariangela Costanzo. Succulents: The Illustrated Dictionary. Portland, Or.: Timber Press, 1994.
“Snapshot.” Accessed September 5, 2015. https://en.wikipedia.org/w/index.php?title=Succulent_plant&oldid=673347553.
“Succulent Plant.” Wikipedia, the Free Encyclopedia, July 27, 2015. https://en.wikipedia.org/w/index.php?title=Succulent_plant&oldid=673347553.
Sunset, and Linda Brandt. Cactus and Succulents. Menlo Park, Ca.: Lane Pub. Co., 1978.