The lily family, Liliaceae, consists of about 15 genera and 610 species of flowering plants within the order Liliales. They are monocotyledonous, perennial, herbaceous, often bulbous geophytes. Plants in this family have evolved with a fair amount of morphological diversity despite genetic similarity.
Originally, the Liliaceae or Lily family 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.
But, botanists in the twentieth century echoed Lindley’s concerns about the lack of a clearly defined grouping for Liliaceae. Johannes Paulus Lotsy suggested four separate families, Liliaceae, Alliaceae, Agapanthaceae and Gilliesiaceae, within the Liliifloren.
This recognised the major groupings that would later be transferred to Amaryllidaceae as subfamilies Allioideae and Agapanthoideae, with Gilliesieae as a tribe within the Allioideae.
The original family Liliaceae in the broad sense (sensu lato, s.l.), which encompassed a large number of differing groups of genera, was highly polyphyletic. This led to botanists increasingly adopting a more narrow monophyletic concept, i.e. strict sense (sensu stricto, s.s.) of the family based on molecular phylogenetic relationships.
Former members of the Liliaceae are now principally classified in different families and subfamilies of the Liliales and Asparagales.