The genus Lilium are herbaceous flowering plants normally growing from bulbs. They comprise a genus of about 110 species in the lily family, Liliaceae. They are important as large showy flowering garden plants. They are important culturally and in literature in much of the world.

Some species are sometimes grown or harvested for the edible bulbs.

The species in this genus are the true lilies. Many other plants exist with "lily" in the common English name, some of which are quite unrelated to the true lilies.

Range

The range of lilies in the Old World extends across much of Europe, the north Mediterranean region, across most of Asia to Japan, south to the Nilgiri mountains in India, and south to the Philippines. In the New World they extend from southern Canada through much of the United States.

They are commonly adapted to either woodland habitats, often montane, or sometimes to grassland habitats. A few can survive in marshland and epiphytes are known in southeast Asia (including L. arboricola). In general they prefer moderately acidic or lime-free soils.

Botany

Christmas Lillium (Lilium longiflorum). 1. Stigma, 2. Style, 3. Stamens, 4. Filament, 5. Petal Lilies are leafy stemmed herbs. They form naked or tunic-less scaly underground bulbs from which they overwinter. In some North American species the base of the bulb develops into rhizomes, on which numerous small bulbs are found. Some species develop stolons. Most bulbs are deeply buried, but a few species form bulbs near the soil surface. Many species form stem-roots. With these, the bulb grows naturally at some depth in the soil, and each year the new stem puts out adventitious roots above the bulb as it emerges from the soil. These roots are in addition to the basal roots that develop at the base of the bulb.

Most species are deciduous, but a few species (Lilium candidum, Lilium catesbaei) bear a basal rosette of leaves during dormancy.

Seeds ripen in late summer. They exhibit varying and sometimes complex germination patterns, many adapted to cool temperate climates.

The large flowers have six tepals, are often fragrant, and come in a range of colours ranging through whites, yellows, oranges, pinks, reds and purples. Markings include spots, brush strokes and picotees. The plants are summer flowering.

Some species formerly included within this genus have now been placed in other genera. These include Cardiocrinum, Notholirion, Nomocharis and some Fritillaria.

Uses

Some lilies, especially Lilium longiflorum, as well as a few other hybrids, form important cut flower crops. These tend to be forced for particular markets; for instance, L. longiflorum for the Easter trade, when it may be called the Easter lily.