The custard-apple, also called bullock's heart or bull's heart, is the fruit of the tree Annona reticulata. This tree is a small deciduous or semi-evergreen tree sometimes reaching 10 metres (33 ft) tall and a native of the tropical New World that prefers low elevations, and a warm, humid climate. It also occurs as feral populations in many parts of the world including Southeast Asia, Taiwan, India, Australia, and Africa. Custard Apple trees are large and spreading, shaded by large, green drooping leaves. The tree sets many light yellow trumpet shaped flowers that emit a pungent, sweet smell especially in the late afternoon when the male pollen sacks burst open. Of these flowers, only a small number will set fruit.The Fruit takes between 20 and 25 weeks to reach maturity in sub-tropical climates where the days are not too warm and the nights not too cool.