The Amaryllidaceae are a family of herbaceous, mainly perennial and bulbous (rarely rhizomatous) flowering plants in the monocot order Asparagales. The family takes its name from the genus Amaryllis and is commonly known as the amaryllis family. The leaves are usually linear, and the flowers are usually bisexual and symmetrical, arranged in umbels on the stem. The petals and sepals are undifferentiated as tepals, which may be fused at the base into a floral tube. Some also display a corona. Allyl sulfide compounds produce the characteristic odour of the onion subfamily (Allioideae).
The family, which was originally created in 1805, now contains about 1600 species, divided into about 70–75 genera, 17 tribes and three subfamilies, the Agapanthoideae (Agapanthus), Allioideae (onions and chives) and Amaryllidoideae (amaryllis, daffodils, snowdrops). Over time, it has seen much reorganisation and at various times was combined with the related Liliaceae. Since 2009, a very broad view has prevailed based on phylogenetics, and including a number of other former families.
The family is found in tropical to subtropical areas of the world and includes many ornamental garden plants and vegetables.
The Amaryllidaceae are mainly terrestrial (rarely aquatic) flowering plants that are herbaceous or succulent geophytes (occasionally epiphytes) that are perennial, with the exception of four species. Most genera grow from bulbs, but a few such as Agapanthus, Clivia and Scadoxus develop from rhizomes (underground stems).
The leaves are simple rather fleshy and two-ranked with parallel veins. Leaf shape may be linear, strap like, oblong, elliptic, lanceolate (lance shaped) or filiform (threadlike). The leaves which are either grouped at the base or arranged alternatively on the stem may be sessile or petiolate and possess a meristem.
The flowers, which are hermaphroditic (bisexual), are actinomorphic (radially symmetrical), rarely zygomorphic, pedicellate or sessile, and are typically arranged in umbels at the apex of leafless flowering stems, or scapes and associated with a filiform (thread like) bract.