This name is a synonym of Crataegus pentagyna subsp. pseudomelanocarpa (Popov ex Pojark.) K.I.Chr..
The record derives from RJP
(data supplied on 2011-10-18)
which reports it as a synonym (record 1713) with original publication details: Flora USSR Flora USSR; 1934 498 1939.
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 pseudomelanocarpa in version 1 of The Plant List.