Edwards E. J., Diaz M., Ecological physiology of Pereskia guamacho, a cactus with leaves, Plant, Cell & Environment, 2006, 29(2):247-256, doi: 10.1111/j.1365-3040.2005.01417.x
Field measurements of Leuenbergeria guamacho (Pereskia guamacho in the older treatment) cover gas exchange, acidity and water relations in Venezuela. They analyse site differences and the dominant role of C₃ photosynthesis.