According to Buddhist tradition, the tree under which the Buddha sat when he attained Enlightenment at Bodh Gaya (near Gaya, west-central Bihar state, India) was a Bodhi tree (Ficus religiosa). A sapling in Sri Lanka, is said to have grown from a cutting from the tree sent to that city by King Ashoka in the 3rd century BC.
The Dhamma Wheel symbol is represented as a chariot wheel with eight spokes. It is the oldest known Buddhist symbol found in Indian art, appearing with the first surviving post-Harappan Indian iconography in the time of the Buddhist king Aśoka. The Dhamma Wheel has been used by all Buddhist nations as a symbol ever since. In its simplest form it is recognized globally as a symbol for Buddhism. The eight spokes represent the Noble Eightfold Path of Buddhism. They are said to have sharp edges to cut through ignorance.
The words on each of the spokes of the wheel are Pali words used to define the Eight Fold Path given by the Buddha.