The most easily confused plants with cacti are the xeric adapted plants of the Euphorbiaceae family. Desert adapted plants in the family perform CAM photosynthesis and resemble cacti by also having strange shapes and thorns. Here is how to tell if a desert plant is in the Euphorbiaceae family.
- Thorns appear in clusters of two, with green leaves sometimes appearing at the same spot. Like cacti, these thorns are modified leaves.
- Flowers are usually unisexual, male or female. This means a single flower will have either carpels or stamens, but both types of flowers appear on the same plant. The family Euphorbiaceae also has a cyanthium, or pseudoanthium, flower structure in which the reproductive structures resemble an oval or sphere that hangs from the end of the reproductive branch and is surrounded by pedal-like bracts.
- If damaged, the plant exudes a white sap.
- Euphorbiaceae is not an exclusively xeric family and species occur throughout the world. However, xeric adapted Euphorbiaceae are native to Africa.