This name is a synonym of Zannichellia palustris subsp. pedicellata (Wahlenb. & Rosén) Hook.f..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 312113) with original publication details: Actes Soc. Linn. Bordeaux 42: lxvii 1888.
This name was in version 1 of The Plant List, record kew-312113.