Although the families Cactaceae and Euphorbiaceae are the most commonly confused, there are additional xeric species that are just as easy to confuse.
The Didiereaceae family looks just like the typical xeric plant and even uses CAM photosynthesis. The Didiereaceae family has the following characteristics:
- Thorns appear one at a time surrounding the stem or branch. Unlike Cactaceae and Euphorbiaceae, Didiereaceae thorns are not derived from modified leaves. Under proper seasonal conditions, small leaves grow through the greyish outer bark to perform photosynthesis.
- Didiereaceae is a small family endemic to Madagascar.