This name is a synonym of Ziziphus mauritiana var. spontanea (Edgew.) R.R. Stewart ex Qaiser & Nazim..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50325949) with original publication details: Trans. Linn. Soc. London 20: 44 1846.
This name was in version 1 of The Plant List, record tro-50325949.