Star Anise is spicier and a bit more pungent than anise seed. Both can slow the pulse and are considered narcotic in high doses (internal only, as far as I have found).
Sweet Fennel is also similar as it also has a high level of anethole (the primary chemical contributing to the well known "licorice smell"). Sweet Fennel starts out sweeter and evolves into a spicy yet smooth scent that smells a bit warmer and 'higher register' than anise seed or star anise.
Longevity of these natural notes is somewhere between top and middle notes, lasting about two to three times as long as most citrus notes, but only about half as long as ylang ylang and just over a third as long as rose otto.