This name is a synonym of Crataegus azarolus var. pontica (K.Koch) K.I.Chr..
The record derives from RJP
(data supplied on 2011-10-18)
which reports it as a synonym (record 87) with original publication details: ; 1853 269 1853.
This name record (from RJP) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Crataegus pontica in version 1 of The Plant List.