Originally, the Liliaceae were defined as having a "calix" (perianth) of six equal-coloured parts, six stamens, a single style, and a superior, three-chambered (trilocular) ovary turning into a capsule fruit at maturity.

[8] Jussieu placed these into the ordo, Lilia in the classis, Stamina Perigyna of the Monocotyledones (monocots), with eight genera (Tulipa, Erythronioum, Methonica, Uvularia, Fritillaria, Imperialis, Lilium, Yucca) only four of which remain in the family.

He defined Lilia as "calix" (perianth) of six equal coloured parts, six stamens, a superior ovary, single style, and trilocular capsule.

The word "Liliaceae" was soon widely used by botanists such as Samuel Frederick Gray,[12] John Lindley,[13] and Pierre-Joseph Redouté[14] in the early nineteenth century.

Gray (1821) provided the first description of Jussieu's scheme in English, identifying two genera occurring in Britain (Tulipa, Fritillaria), distinguished by the absence or presence of basal nectaries.

His key used the presence of six equal stamens, a single style, a simple petaloid (undifferentiated tepals resembling petals) perianth and a trilocular capsule with flat seeds to identify the family.

[18] Candolle also instituted the concept of ordered ranks, based on classes, subclasses, familles (Latin: ordines naturales) and tribus (tribes),[10] subdividing the Liliaceae.

Lindley was the first post-Linnaean English systematist, publishing his work in 1830,[19] and following the reasoning of Jussieu he used the term tribe to describe the Liliaceae as a division of the hexapetaloid monocots, characterised by a superior ovary, highly developed perianth, inward turning anthers, a trilocular polyspermous capsule and seeds with a soft spongy coat.

[20] In this work he unhappily acknowledged the confusing array of different approaches to the classification of the Liliaceae, the lack of a clear definition, and the great diversity in the circumscription of the order, which had expanded vastly, with many subdivisions.

[24] The new phyletic approach changed the way that taxonomists considered plant classification, incorporating evolutionary information into their schemata, but this did little to further define the circumscription of Liliaceae.

[27] The major works in the late nineteenth and early twentieth century employing this approach were in the German literature, the Eichler (1875–1886), Engler and Prantl (1886–1924) and Wettstein (1901–1935) systems.

[34] Cronquist was a "lumper" preferring a small number of very large groupings and his classification of the Liliaceae represented the greatest expansion of the family to date.

Where Cronquist saw one family, Dahlgren saw forty distributed over three orders (predominantly Liliales and Asparagales), reducing Liliaceae to ten genera (see Table 3).

[48] The establishment of major new clades necessitated a departure from the older but widely used classifications such as Cronquist and Thorne, based largely on morphology rather than genetic data.

[54] This newly, more narrowly (sensu stricto, s.s.) circumscribed Liliaceae, corresponded to the emerging circumscription of the family in the Angiosperm Phylogeny Group system (1998).

The monophyly of these newly defined orders is supported by cladistic analysis based on morphology, 18S rDNA, the plastid gene rbcL, and other DNA sequences.

[83] This redistribution resulted in considerable changes both in the suprafamilial positioning of Liliaceae within the overall APG classification (as shown in Table 1 below), as well as the subfamilial structure (see Suprageneric subdivisions).

[95] Sequencing of the rbcL and trnL-F plastid genes revealed four main Liliales lineages:[63] The original family Liliaceae in the broad sense (sensu lato, s.l.

Former members of the Liliaceae are now principally classified in different families and subfamilies of the Liliales and Asparagales as shown in the phylogeny represented in Cladogram I.

[50][95] Sequencing of the rbcL and matK chloroplast genes of Lilium and related genera[96] confirmed the circumscription of the family in the sensu stricto usage of Tamura (1998).

Corsiaceae Campynemataceae MelanthiaceaeL Petermanniaceae ColchicaceaeL LuzuriagaceaeL AlstroemeriaceaeL RipogonaceaeL PhilesiaceaeL SmilacaceaeL Liliaceae sensu stricto Orchidaceae BoryaceaeL BlandfordiaceaeL LanariaceaeL AsteliaceaeL HypoxidaceaeA IxioliriaceaeA Tecophilaeaceae Doryanthaceae Iridaceae XeronemataceaeL XanthorrhoeaceaeL Amaryllidaceae AphyllanthaceaeL ThemidaceaeL HyacinthaceaeL AgavaceaeL/A LaxmanniaceaeL AsparagaceaeL RuscaceaeL commelinids The major diversification amongst the Angiosperms (flowering plants) can be dated to the end of the Early Cretaceous period which stretched from 146 to 100 million years ago (mya).

[78][54][102] The southern hemisphere intercontinental distributions of Liliales suggests a connection to Gondwana, whose breakup into western (Africa, South America) and eastern (Australia, Antarctica, Madagascar, India) portions occurred at 180–150 mya, and the final separation of the western portion into Africa and South America at 80 mya coinciding with the emergence of the Liliales.

On the other hand, Clintonia-Medeola (Medeoleae) may have appeared in North America but subsequently underwent intercontinental dispersal (although some evidence points to a Eurasian origin).

The Calochortaceae sensu Tamura (Streptopoideae and Calochortoideae) appears to have evolved in western North America, with subsequent colonisation of East Asia by Streptopus and the ancestral Tricyrtis.

[54] In addition such molecular studies show that share characteristics do not necessarily indicate descent from a common ancestor but rather may arise from adaptive convergence in similar habitats.

Within this clade, Lilieae s.s. are characterised by papillose tepals (with the exception of Fritillaria) and numerous fleshy bulb-scales as well as a morphologically distinct karyotype with two long metacentric chromosomes and 10 telocentrics of medium length.

), many attempts have been made to form supageneric classification systems, organizing the genera into subfamilies, tribes, or other suprageneric taxa (taxonomic groupings between genus and family).

[94] By 1813, Candolle recognised five subdivisions which he called tribes (Asparagées, Trilliacées, Asphodelées, Bromeliées, Tulipacées),[17] all of which Jussieu had made separate families, with the exception of Tulipa, which was a genus within the Liliaceae.

Sequencing of the rbcL and matK chloroplast genes established monophyly for Clintonia, but with separate clades corresponding to the two areas of distribution.

[93] In 2013, Kim et al. proposed further subdivision, placing the two genera of Calochortoideae (Calochortus and Tricyrtis) into subfamilies of their own and splitting off Gagea from the rest of Tulipeae by resurrecting the tribe Lloydieae.