Casimiroa edulis, with English common names casimiroa, white sapote, and Mexican apple, and known as cochitzapotl in the Nahuatl language (meaning '"sleep-sapote") is a species of tropical fruiting tree in the family Rutaceae, native to eastern Mexico and Central America south to Costa Rica. The genus is named for "an Otomi Indian, Casimiro Gómez, from the town of Cardonal in Hidalgo, Mexico, who fought and died in Mexico's war of independence." 
Mature Casimiroa edulis trees range from 5–16 metres (16–52 ft) tall and are evergreen. The leaves are alternate, palmately compound with 3–5 leaflets, the leaflets 6–13 cm long and 2.5–5 cm broad with an entire margin, and the leaf petiole 10–15 cm long.
The fruit is an ovoid drupe, 5–10 cm in diameter, with a thin, inedible skin turning from green to yellow when ripe, and an edible pulp, which can range in flavor from bland to banana-like to peach to pear to vanilla flan.photo 1photo 2photo 3 The pulp can be creamy-white in green skin varieties or a beige-yellow in yellow skin varieties and has a smooth texture similar to ripe avocado. It contains from one to five seeds that are said to have narcotic properties.
In the past 40 years, experiments have been carried out on the white sapote's seeds that have yielded the identity of many pharmacologically active compounds, including: N-methylhistamine, N,N-dimethylhistamine and histamine. It also contains 2′,5,6-Trimethoxyflavone, 2′,5,6,7-tetramethoxyflavone (zapotin) and 5-hydroxy-2′,6,7-trimethoxyflavone (zapotinin).
The fruit has long been thought to produce drowsiness, as claimed by Francisco Hernández de Toledo in the 16th century. However this may be a misinterpretation of the Nahuatl name of the plant, cochitzapotl (meaning '"sleep-sapote"), as its seeds were processed to produce a poison by the Aztecs and the seeds and leaves, but not fruit pulp, of the plant contain sleep-inducing compounds.
Unlike the mamey sapote, white sapote is a member of the family Rutaceae, to which citrus belongs. The black sapote is also unrelated and is actually a species of persimmon. This confusion may be because "sapote" comes from the Nahuatl (Aztec) word tzapotl, used to describe all soft, sweet fruit. Commonly grown in Northern New South Wales, Australia, and often mistaken for a persimmon, although these two fruits are unrelated.
|Wikimedia Commons has media related to Casimiroa edulis.|
- "Casimiroa edulis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2009-02-06.
- Murillo G, Hirschelman WH, Ito A, et al. (2007). "Zapotin, a phytochemical present in a Mexican fruit, prevents colon carcinogenesis". Nutrition and Cancer. 57 (1): 28–37. doi:10.1080/01635580701268097. PMID 17516860.
- Sondheimer, F (1960). "Constituents of Casimiroa edulis Llave et Lex.—VI 2′,5,6-Trimethoxyflavone, 2′,5,6,7-tetramethoxyflavone (zapotin) and 5-hydroxy-2′,6,7-trimethoxyflavone (zapotinin)". Tetrahedron. 9 (3–4): 139–144. doi:10.1016/0040-4020(60)80001-4.
- Maiti A, Cuendet M, Kondratyuk T, Croy VL, Pezzuto JM, Cushman M (Jan 2007). "Synthesis and cancer chemopreventive activity of zapotin, a natural product from Casimiroa edulis". Journal of Medicinal Chemistry. American Chemical Society. 50 (2): 350–5. doi:10.1021/jm060915+. PMC . PMID 17228877.
- Morton, J.; Julia F. Morton (1987). "White Sapote: Casimiroa edulus Llave". Fruits of warm climates. Miami, Florida. pp. 191–196.
- Boning, Charles R. (2006). Florida’s Best Fruiting Plants: Native and Exotic Trees, Shrubs, and Vines. Sarasota, Florida: Pineapple Press, Inc. p. 211. ISBN 1561643726.
- Huxley, A. (1992). New RHS Dictionary of Gardening. Macmillan.
- Henry A. & Vera-Caletti P. 2010. – Usages du sapotier blanc (Casimiroa spp.) en Mésoamérique. Histoire, ethnographie et botanique. Anthropobotanica 1.7-2010. in French with English abstract