This name is a synonym of Acorus calamus var. americanus Raf..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 2297) with original publication details: New Fl. 1: 57 1836.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:84002-1.
This name was in version 1 of The Plant List, record kew-2297, and has not been changed.