Bel Fruit / Beal Fruit

Bael or Bilwa (wood apple tree or Bengal quince) is an important tree in Indian culture, and is believed to be known to Indians since the time the Vedas were composed during 2000 BC – 800 BC. Bael or bilwa tree is planted in and around most temples in India. The tree has been mentioned in Ayurvedic texts like Charaka Samhita.

The fruit is widely used in religious rituals. In Hinduism the tree is sacred as it is known to grew out of Goddess Parvati's sweat. It is used in the worship of Shiva as a ritual offering, who is said to favor the leaves. The trifoliate leaves symbolize the trident that Shiva holds in his right hand.

The mention of the Bael fruit has been made in the Yajur Veda. This tree has great mythological significance and is grown abundantly around the vicinity of the temples. The Bael tree, which is indigenous to India, is one of the most useful medicinal plants in India.

The Beal tree is also sacred to the Jains. It is said the 23rd Tirthankara, Bhagwan Parasnathji attained "Nirvana" enlightenment under a Bael tree. Besides religious significane, almost all parts of the tree have medicinal qualities Bael is an ingredient in many Ayurvedic and Siddha formulations. 

Shiva Purana explains Bael tree as manifestation form of lord shiva himself and all great shrines are said to reside at its base.

Many Hindus have bael trees in their gardens
The fruits were used in place of coconuts before large-scale rail transportation became available. The fruit is said to resemble a skull with a white, bone-like outer shell and a soft inner part, and is sometimes called seer phael (head-fruit). However, it is quite likely that, the term 'Seer Phal' has coined from the Sanskrit term 'ShreePhal, which again is a common name for this fruit.
At the time of abhishek offers too shivalingum.Daily worshiped in shravan months or four mondays shravan somwar too pleased shivaalong with belpatra,Dhatura,vibhutee etc.