Because of its rarity, Anise Hyssop is not normally thought of as a prairie species in Illinois, nor does it appear in many field guides of prairie plants for the tallgrass prairie. This plant does occur in the northwestern area of the tallgrass prairie, however, with a few scattered remnant populations elsewhere. Other members of this genus are woodland species. One of them, Agastache scrophulariaefolia (Purple Giant Hyssop), has flowers with similar coloration to Anise Hyssop. However, the foliage of Purple Giant Hyssop doesn't have an anise scent and the the undersides of the leaves are green, rather than white. Purple Giant Hyssop is more pubescent or hairier than Anise Hyssop, and it tends to be a taller plant. The calyx of each flower remains green for this species, unlike Anise Hyssop, where each calyx assumes a coloration that is more similar to the flowers. This latter characteristic can cause Anise Hyssop to look like it is in flower, even when it is not.