This name is a synonym of Phragmites australis subsp. altissimus (Benth.) Clayton.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 433930) with original publication details: Feddes Repert. 93: 20 1982.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:921276-1.
This name was in version 1 of The Plant List, record kew-433930.