This is sacred tree for Indians. It was under this tree that Gautam Buddha attained enlightenment on the full moon day of Vaisakh. In the second mission sent by Ashoka the great, to Sri Lanka was led by Sanghamitra, the emperor's sister. She took with her a branch of the sacred Bo-tree which still flourish there!
The banyan tree is one of the species of fig tree and is technically denoted as Ficus Bengalensis. It can grow to a height of over seventy five to hundred feet and sends out branches parallel to the ground supported by aerial roots, called proproots!
There is a tree at Adya, in Madras city (Chennai), that covers more than an acre of ground with its branches, which may number into hundreds! This is a tree native to India and tropical Africa. According to a legend Alexender during his adventure in India sheltered some 7000 of his soldiers in a single tree which had some 3000 branches!