Bel patra is a leaf of Bel, Bilwa tree (Aegle marmelos). It is widely used in worship of Hindu deities, especially to Lord Shiva Shiva. The trifoliate or the three prong Bel leaf signifies the holy Trinity: Lord Brahma, Lord Vishnu and Lord Shiva. As in Hindu mythology, it is believed that Goddess Parvati resides in all her forms in the leaves, fruits and roots of Bel tree, and therefore, Lord Shiva is extremely fond of the bilwa tree and its leaves. Therefore, on the occasion of Mahashivratri, Lord Shiva is offered with the Bilwa leaves.