The record derives from RJP (data supplied on ) which reports it as a synonym (record 34035) with original publication details: Systema vegetabilium. Editio decima quarta Systema vegetabilium. Editio decima quarta; 1784 465 1784.
Full publication details for this name can be found in IPNI:
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 laevis in version 1 of The Plant List.