As of January 2018, APG IV has placed Fumarioideae as a sub-family in Family Papaveraceae, Order Ranunculales. Flora of North America says:"Most European and some American systematists treat Fumariaceae as a subfamily of Papaveraceae. However, although a few taxa are morphologically intermediate, the members of Fumarioideae generally are quite distinct from those of Papaveraceae in several respects, including floral symmetry, sap character, and stamen number and fusion. Please see FNA for additional information. For now, I am leaving things as they are.