This name is a synonym of Campanula sibirica subsp. elatior (Fomin) Fed..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym and as an illegitimate name (record 364548) with original publication details: Fl. URSS 24: 460 1957.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:140250-1.
This name was in version 1 of The Plant List, record kew-364548, and has not been changed.