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 2335) with original publication details: Dansk Bot. Ark. 23: 416 1968.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:84026-1.
This name was in version 1 of The Plant List, record kew-2335, and has not been changed.