These succulent plants are also called “fleshy” plants, but that doesn’t mean that they’re fatty. The name “succulent” comes from the Latin word succus, meaning “juice” or “sap.”
Succulents have special water-storage cells in the fleshy tissues of their leaves, stems or roots. All cacti are succulents, but not all succulents are cacti. In addition to members of the Cactaceae family, there are several other important families of succulents, such as Crassulaceae, Aizoaceae, and Euphorbiaceae.
The caudex, an adaptation for surviving periods of drought
A large number of plants protect themselves from the heat by going into dormancy during the hottest, driest period of the year. These are often plants with a caudex, which is a thick woody rootstock.
During dormancy, the caudex, a storage organ, enables the plant to survive. When conditions become favorable, stems and tender leaves emerge from the caudex. These tissues last only as long as the growing season, and require a certain degree of humidity, fog or morning dew.
The elephant’s foot (Dioscorea elephantipes) from South Africa – with its spectacular caudex reminiscent of just that, an elephant`s foot – is an example of this type of plant.