CUSTARD APPLE, a name applied to the fruit of various species of the genus Anona (family Anonaceae). The members of this genus are shrubs or small trees having alternate, exstipu late leaves, and flowers with three small sepals, six petals arranged in a double row and numerous stamens. The fruit of A. reticulata, the common custard apple, or "bullock's heart" of the West Indies, is dark brown in colour, and marked with depressions, which give it a quilted appearance ; its pulp is reddish-yellow, sweetish and very soft (whence the name) ; the kernels of the seeds are said to be poisonous. The sour-sop (q.v.) is the fruit of A. muricata, native of the West Indies. The sweet-sop (q.v.) is produced by A. squamosa, a native of the East Indies and widely cultivated in the tropics. A. Cherimolia yields the Peru vian cherimoya, which is a fruit of superior flavour, and much esteemed by the Creoles. A. palustris, alligator-apple, or cork-wood, a native of South America and the West Indies, is valued for its wood, which serves the same purposes as cork; the fruit, com monly known as the alligator-apple, is not eaten, being reputed poisonous. (See ANONACEAE; CHERIMOYA.)