Liliaceae

Liliaceae, the lily family, is a family of flowering plants in the order Liliales, within the monocots. The modern circumscription (APG system) places a relatively small core of genera in Liliaceae, with many former members now treated in related families. Notable genera in the core include Lilium (lilies), Tulipa (tulips), Fritillaria, Erythronium (dogtooth violets), and Cardiocrinum. The family is distributed mainly in temperate regions of the Northern Hemisphere and is widely cultivated for ornament.

Species are mostly herbaceous perennials, frequently bulbous; leaves are slender, often linear, and may be arranged alternately or in two ranks. Flowers are usually large and conspicuous, bisexual, with a perianth of six tepals arranged in two whorls, often forming a tube or funnel. There are six stamens and a single, superior ovary with three locules. The fruit is typically a dry capsule containing numerous seeds.

Under APG classifications, Liliaceae sensu lato has been narrowed; many genera formerly placed in Liliaceae have been reassigned to Melanthiaceae, Asparagaceae, or Smilacaceae, depending on the lineage. The remaining Liliaceae s.s. includes a core of genera such as Lilium, Tulipa, Fritillaria, and Erythronium. The circumscription remains subject to ongoing revision as molecular studies clarify relationships within Liliales.

Many species are valued as ornamentals and have long been cultivated for flower displays, cut flowers, and bulbs. They are grown in temperate gardens and as greenhouse crops, and several taxa have become naturalized beyond their native ranges. Some members produce bulbs or compounds that are toxic to grazing animals, and lily foliage or nectar can cause irritation to some people and animals.