The Ashoka tree (lit., "sorrow-less") is a flowering tree considered sacred throughout India and Sri Lanka where it is found. It is prized for its beautiful foliage and flowers. The Lord Buddha was born under this tree in Lumbini. Also Lord Mahavira renounced the world under the Ashoka tree in Vaishali. The Hindus regard it as sacred, being dedicated to Kama Deva, God of Love. The tree gets a mention in the Ramayana as the Ashoka Vatika (garden of Ashoka trees) where Hanuman first meets Sita.
The botanical name for the Ashoka Tree is Saraca asoca or Jonesia Ashok. It belongs to the legume family and genus Saraca. One of its varieties is a very handsome, small, erect evergreen tree, with deep green foliage. Its flowers are very fragrant and are bright orange-yellow in color and later turn red. Found in the foothills of central and eastern Himalayas, almost all over the northern plains of India as well as on the west coast of Bombay, its flowering season is around February to April. Another of its variety is larger and highly spreading. The erect variety (which appears like a poplar) is extremely common in the gardens of modern Indian households.
Other names for the Ashoka Tree include: Sita-Ashok, Anganapriya, Asogam, Asokada, Ashopalava, Asok, Ashok, Asoka, Asoka Tree, Asupala, Gandapushpa, Kankelli, Kenkalimara, Thawgabo, Vand ichitrah.The above inf. taken from Wikipedia link:http://en.wikipedia.org/wiki/Ashoka_tree