Daruja lingas are Shivlings made of wood. Wood of certain trees are only is used in the making of the linga. The wood of trees that are used to prepare Daruja linga are Shami, Madhuka, Karnikara, Manduka, Tinduka, Arjuna, Pippala, Udumbara, Khadira, Chandan, Sala, Bilva, Badara and Devadaru.
It is also mentioned in some texts that wood of all trees that have barks can be used. Trees that have milky latex oozing out when cut is said to be ideal for making the linga. Jackfruit tree wood is widely used in
South India for making lingas.
Before cutting the tree for a making a Shivling, prayers have to be offered to the tree, Mother Earth, and all living beings residing on the tree. Permission is to be taken from the tree and the living beings residing on it. If the tree is hosting large number of birds, then the tree is to be avoided.
One can also use only a big trunk of the tree for making Daruja Linga. So the entire need not be cut down.
Details regarding the preparation of Daruja Linga are found in the Kamikagama and other texts.