It is combination of 9 kind of sticks in one pocket.
Any venture starts with invoking the blessings of the Almighty for success. As part of the holy fire in the invocation is a bundle of sticks called in Sanskrit, "Samithu".
Samithu (wood used for homam) : erukku, purasu, karungali, naaurivi, arasu, athi, vanni, arugan grass etc.
Samithu is the bundle of dry sticks with which the fire is invoked in any Homam. The sticks of Erukku, Purasu, Karungali, Arasu, Athi, Vanni that fall down themselves and get dried are collected and bundled for offering to God by invoking fire. Also, the dried grasses like Nayuruvi, Arugan, etc. also forms part of Samithu.
For those who are doing self enquiry they may be having yagna in which all the thoughts are the SAMITHU. The question will be (who I am ) will be the ghee falls into the fire of yagna.
The ghee and the samithu all get burn, the prasam is the thoughtless stage, which gives the enlightenment.