Taxonomy
Acorus americanus was formerly classified as Acorus calamus var. americanus. The species name, "americanus" simply indicates that this is an American species of Acorus. It differs only in being a fertile diploid (2n = 24)], whereas most of the A. calamus of Europe and Asia is a sterile triploid species, that only spreads asexually. Diploid plants in northern Asia may be part of A. americanus.Also as a diploid it does not produce b-asarone.
Read more about this topic: Acorus Americanus