We described the chemical transition that takes place in the fruits and seeds of laurel cherry (Prunus caroliniana), an evergreen tree native to the subtropical United States with bird-dispersed seeds. The unripe fruits contain cyanide and release it when the fruit tissue is damaged, whereas ripe fruits are cyanide free. The reverse was true for seeds: immature seeds were free of cyanide whereas mature seeds were cyanogenic. We also described the reproductive phenology of laurel cherry and suggest that the chemical trait we described protects the fruits during their unusually long maturation period.