The record derives from RJP (data supplied on ) which reports it as a synonym (record 18740) with original publication details: Cyclopedia of American horticulture Cyclopedia of American horticulture; 1900 396 1900.
⥇ A cross-taxon basionym link was ignored while processing this record, see Crataegus oxyacantha var. pteridifolia .
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 monogyna in version 1 of The Plant List.