This name is a synonym of Acorus calamus var. angustatus Besser.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 2340) with original publication details: Prodr. Syst. Aroid. 578 1860.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:84031-1.
This name was in version 1 of The Plant List, record kew-2340, and has not been changed.