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 2323) with original publication details: Repert. Spec. Nov. Regni Veg. Beih. 12: 312 1922.
This name was in version 1 of The Plant List, record kew-2323, and has not been changed.