Ackee: a Jamaican fruit
The ackee is a popular Jamaican fruit that is not allowed to enter the United States because it's highly dangerous. When the fruit turns red, it's ripe. But when it's yellow, it's teeming with toxic levels of hypoglycin A, which, when consumed, could result in vomiting, hypoglycemia, or even death. The black seeds on the other hand, are always poisonous.