Elephant apple (Dillenia indica), known as chalta in Bengali and Hindi and ou tenga in Assamese, is a large, hard, greenish fruit of the Dilleniaceae family native to the moist forests of the Indian subcontinent and Southeast Asia. What looks like a single fruit is actually a cluster of fleshy, overlapping sepals enclosing a sour, fibrous, gelatinous core — too acidic and astringent to eat raw, and prized instead for tart curries, chutneys and pickles across northeast India and Bangladesh.