This name is a synonym of Syzygium cordifolium subsp. spissum (Alston) P.S.Ashton.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 22105248) with original publication details: Symb. Bot. 2: 58 1791.
This name was in version 1 of The Plant List, record tro-22105248, and has not been changed.