Although distributed throughout the world, species of Liliales are most common in subtropical and temperate regions. The greatest number of species and individuals are found in the Northern Hemisphere.

The leaves of Liliales are either straplike with parallel venation or ovate with palmate veins and reticulate minor venation (Smilacaceae). The leaves of Alstroemeria (known as lily of the Incas, in family Alstroemeriaceae) and Bomarea are twisted (resupinate) so that the leaf undersurface faces upward.

Liliales is a source of pharmaceutical products. colchicine, an important medicinal compound, and related alkaloids characterize a group of Old World genera, including Colchicum (family Colchicaceae) and Gloriosa. A number of genera of the Northern Hemisphere, including Veratrum (family Melanthiaceae) and Zigadenus (star lily, in family Melanthiaceae), have the alkaloid veratrine and similar compounds.

The order Liliales was formerly circumscribed by some taxonomists to include many morphologically diverse taxa within the monocotyledons. Based primarily upon molecular data, the taxa that were formerly included within Liliidae, Liliales, and Liliaceae have now been divided between three main orders of monocotyledons: Liliales, Asparagales, and Dioscoreales. Asparagales, the largest and taxonomically most diverse of these three orders, is characterized by possessing seeds with a distinctive outer layer containing phytomelan, a carbonaceous substance causing the dense black coloration of the seeds, although this feature is not universal in the order. Liliales is now much reduced and defined by the presence of perigonal nectaries at the base of the tepals, extrorse anthers (the anther opening facing outward), and sometimes spotted petals. Further rearrangements of genera within the families of this order are expected before a stable taxonomy will be reached. For further information on botanical classification systems, see angiosperm.

Alstroemeria, an important ornamental plant genus, belongs to the family Alstroemeriaceae, which is distributed in the New World from Chile and Argentina to Mexico. Species within this family are herbaceous herbs or climbers with distinctive resupinate leaves and flowers clustered in umbels. The genus Bomarea is a characteristic vine of the high Andean mountains with brightly coloured flowers pollinated by hummingbirds.