Lilioid monocots

Lilioid monocots (lilioids, liliid monocots, petaloid monocots, petaloid lilioid monocots) is an informal name used for a grade of five monocot orders (Petrosaviales, Dioscoreales, Pandanales, Liliales and Asparagales) in which the majority of species have flowers with relatively large, coloured tepals, broadly similar to those of lilies, hence "lily-like". Petaloid monocots refers to the flowers having tepals which all resemble petals (petaloid). The taxonomic terms Lilianae or Liliiflorae have also been applied to this assemblage at various times. In older classification systems, still found in many books and other sources, many of the species in this group of plants were put into a very broadly defined family, Liliaceae sensu lato or s.l. (lily family) . Within the monocots they were distinguished from the Glumaceae.

The development of molecular phylogenetics and methods cladistic theory resulted in a dismemberment of the Liliaceae and its subsequent redistribution across three lilioid orders (Liliales, Asparagales and Dioscoreales). Subsequent work has shown that two other more recently recognised orders, Petrosaviales and Pandanales also segregate with this group, resulting in the modern concept of five constituent orders within the lilioid monocot assemblage. This has resulted in treating monocots as three informal groups, alismatid, lilioid and commelinid monocots. The lilioids are paraphyletic in the sense that commelinids form a sister group to Asparagales.