The White Sapote (Casimiroa edulis LaLlave) is a fruit tree and medicinal plant of Mesoamerican origin. In Mexico, it is widely cultivated in home gardens. Commercial plantations are reported from California, Florida, Israel, Australia and New Zealand. The traditional cultivation leads to strongly fragmented populations and to considerable variation in fruit and other characteristics. Within the project “Systematics and ethnobotany of the genus Casimiroa (Rutaceae)” we are studying this variation and will present preliminary results of fieldwork in the center and north of Mexico. Particular emphasis will be on characteristics relevant for breeding, such as flavor and consistency of the mesocarp, fruit size and shape, exocarp thickness and stone size. Also, the shapes of the stones show regionalized patterns, which may be useful for the interpretation of archeological remains.

Key words: Casimiroa edulis, fruit tree, Mexico, Rutaceae, variation