Though both have a distinctive liquorice flavour, star anise and anise seed are spices that come from two entirely different plants. The plants and the resulting spices have other differences, as well.
Star anise has the scientific name Illicium verum and is an evergreen tree native to China. The tree can grow up to 40 feet tall with clusters of leathery leaves and bell-shaped pink-to-red or greenish-yellow flowers. The fruit that follows is made up of eight woody pods joined in a star shape. Each pod has one liquorice-flavoured seed.
Anise, scientific name Pimpinella anisum L., is a annual herb native to the Mediterranean and Egypt and can be grown in the United States as a non-invasive alternative to fennel. The plant grows 2 feet tall and produces parsley-like lower leaves and lacy upper leaves and umbrella-like white flowers. The 1/6-inch oval seeds are slightly curved and produced in individual pods.
Anise is said to have the better flavour, and the seeds are pressed into oil and used as flavouring in liquorice and other food, as the seeds are not attractive in food products. The chopped leaves may also be used as flavouring. Dried star anise pods are used in Chinese five-spice mix. The attractive seed pods are often used whole, though the seeds may be pressed into oil, as well. Both seeds have medicinal uses; anise is used in perfumes and soaps and to create the liquor anisette.