There are three plants that react similarly on the human taste buds, Illicium verum, Illicium anisatum and Pimpinella anisum.
The first two are of the same genus and are often refereed to as Japanese Star Anise which is a native of SE China and Vietnam. It is a small tree and the seed provides the flavour.
Pimpinella anisum is similar to fennel and is often used to flavour food and drinks. It is native to SW Asia and the Mediterranean.
I prefer the taste of the Star Anise as compared to Fennel and Pimpinella.
Like many other botanical s the best way extract flavour is use a small laboratory still to extract the plant oil. They used to be available from a supplier in Adelaide. Highly recommended if you intend to experiment with flavours.