The showy and large flowered plants of the genus Lilium are the true lily plants. They are placed in the lily family, the Liliaceae.

Lilies are rhizomous plants of the northern temperate regions. Their range in the Old World extends across much of Europe, the north Mediterranean, 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.

The large showy flowers are six-petalled, often fragrant, and come in a range of colours ranging through whites, yellows and reds, sometimes with other markings.

The plants are summer flowering, and they have a winter resting period. Most species are deciduous, but Lilium candidum bears a basal rosette of leaves for much of the year. The bulb-like scaly rhizomes are formed only for storage tissue, and have no protective tunics. Flowers are formed at the top of a single erect stem, with leaves being borne at intervals up the stem.

Lilies are commonly adapted to either woodland habitats, often montane, or sometimes to grassland habitats. A few can survive in marshland and a single one is known to live as an epiphyte (L. arboricola).

pollen of Lilium auratum (Oriental Lily)
Back-scattered electron microscope image

Numerous cultivated forms are now grown for gardens.

The term Lily (generally with a modifier, such as "water lily", "daylily", or "blackberry lily") is also applied to a large number of other plants, which may resemble it to a greater or lesser extent. Most of them are quite unrelated to the true lilies.

Liliums are propagated by division of the rhizomes and by seed. Rhizomes should be planted in autumn.

There are reports of nephrotoxicosis (kidney failure) in cats which have eaten some species of Lilium and Hemerocallis. [1] (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12680447&dopt=Abstract)