This name is a synonym of Crataegus dahurica var. laevicalyx (J.X.Huang, L.Y.Sun & T.J.Feng) T.C.Ku & Spongberg.
The record derives from RJP
(data supplied on 2011-10-18)
which reports it as a synonym (record 19017) with original publication details: ; 1991 25, t. 1991.
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 laevicalyx in version 1 of The Plant List.