Trilliaceae is the botanical name of a family of flowering plants. A botanical name is a formal scientific name conforming to the International Code of Botanical Nomenclature (ICBN and if the plant is a Cultigen, the In Biological classification, family ( Latin The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group The family has been recognised as distinct since 1846 when it was recognized; this table  for a summarizes the placement of these taxa. The family has been recognized by taxonomists such as Takhtajan, Dahlgren, Thorne, and Watson & Dallwitz; other taxonomists have considered these plants to belong to the family Liliaceae. The Liliaceae, or the lily family, is a family of Monocotyledons in the order Liliales. The APG II system, of 2003 (unchanged from the APG system, of 1998), does not recognize such a family either and assigns the plants involved to family Melanthiaceae. Melanthiaceae is a family of flowering perennial herbs in the Northern Hemisphere. One problem with this recognition is the lack of morphological synapomorphies for the family Melanthiaceae; this chart  provides a summary of the characters in each of the major groups. In Evolutionary biology, a synapomorphy is a derived Character state shared by two or more terminal groups ( taxa included in a Cladistic analysis Melanthiaceae is a family of flowering perennial herbs in the Northern Hemisphere.
Nevertheless, some taxonomists still recognize a separate family Trilliaceae. The most important genus in North America is Trillium, and the taxonomy of that genus has always been controversial. Trillium is a genus of about 40-50 species of perennial herbaceous Flowering plants native to temperate regions of North America and Asia To paraphrase what Steven Elliott wrote of the genus Trillium in 1817,
A recent treatment (Farmer and Schilling 2002) stated that the family Trilliaceae, which exhibits an arcto-tertiary distribution, comprises six genera. Three of these exhibit a wide distribution:
Three are monotypic, endemic genera:
Paris quadrifolia in flower
Paris quadrifolia in fruit
Paris quadrifolia from Sturm (1796)