Annonaceae

Annonaceae (custard-apple, or annona family) is the largest family of the magnolia order. It has 129 genera and 2,400 species.  

Many species are valuable for their large pulpy fruits. Some are useful for their timber, while others are prized as ornamentals. The family consists of trees, shrubs, and woody climbers found mainly in the tropics, with a few species in temperate regions.

Their fruits defend themselves against some herbivores. Eating the neotropical plant Annona muricata (soursop, graviola, guanabana) is a causal agent in "atypical Parkinsonism". The causative agent, annonacin, is present in the seeds and leaves of many of the Annonaceae, though not in any significant quantity in the fruit flesh. It is thought to be responsible for up to 70% of Parkinsonian conditions in Guadeloupe. Exposure is typically through traditional food and natural medicines. It is hard to interpret this. Presumably some favoured herbivores can eat it without ill effects. In some plants, seeds contain irritants to encourage early defecation.

Sources
 Integrated Taxonomic Information System. Annonaceae
University of Hawaii, Botany Department. Annonaceae

 References