Amrit (ambrosia), Sassi (moon), Dhena (wish-fulfilling cow), Lakshmi, Kalpataru (wish-fulfilling tree), Sikhira (the horse) and Sunagar (Dhanwantara) all came out from the ocean, the lord of the rivers, but because of its past actions,it still remains saltish. (Dhanasari Trtlochan, p. 695) Kalpataru is also called Parijata. It was produced when the milk-ocean was churned by god and demons. It was kept in Amaravati, the heaven of Indra.

Once Krishna visited the heaven and on the request of Satyabhama, he brought it to Dwarka after a great battle. The tree returned to heaven after Krishna left this mortal world. Like Surabhi (the cow) this tree fulfilled all the wishes. See: Parijata

References :

1. Kohli, Surindar Singh (ed), Dictionary of Mythological References in Guru Granth Sahib, 1993