The Asparagales are an order of plants, and on this page the structure of the order is used according to the APG III system. The order takes its name from the family Asparagaceae and is placed in the monocots. The order is clearly circumscribed on the basis of DNA sequence analysis, but is difficult to define morphologically, since its members are structurally diverse. The APG III system is used in World Checklist of Selected Plant Families from the Royal Botanical Gardens at Kew. With this circumscription, the order consists of 14 families (Dahlgren had 31) with approximately 1120 genera and 26000 species.

Thus although most species in the order are herbaceous, some no more than 15 cm high, there are a number of climbers (e.g., some species of Asparagus), as well as several genera forming trees (e.g. Agave, Cordyline, Yucca, Dracaena), some of which can exceed 10 m in height. Succulent genera occur in several families (e.g. Aloe). One of the defining characteristics of the order is the presence of phytomelan (phytomelanin), a black pigment present in the seed coat, creating a dark crust. Phytomelan is found in most families of the Asparagales (although not in Orchidaceae, thought to be a sister to the rest of the group). Almost all species have a tight cluster of leaves (a rosette), either at the base of the plant or at the end of a more-or-less woody stem; the leaves are less often produced along the stem. The flowers are in the main not particularly distinctive, being of a general 'lily type', with six tepals, either free or fused from the base. From an economic point of view, the order Asparagales is second in importance within the monocots to the order Poales (which includes grasses and cereals). Species are used as food and flavourings (e.g. onion, garlic, leek, asparagus, vanilla), as cut flowers (e.g. freesia, gladiolus, iris, orchids), and as garden ornamentals (e.g. day lilies, lily of the valley, Agapanthus).

Families included by the APG Order Asparagales Link Family Amaryllidaceae J.St.-Hil. (including Agapanthaceae F.Voigt, Alliaceae Borkh.)The name 'Alliaceae' has also been used for the expanded family comprising the Alliaceae sensu stricto, Amaryllidaceae and Agapanthaceae (e.g. in the APG II system). 'Amaryllidaceae' is used as a conserved name in APG III. Family Asparagaceae Juss. (including Agavaceae Dumort. [which includes Anemarrhenaceae, Anthericaceae, Behniaceae and Herreriaceae], Aphyllanthaceae Burnett, Hesperocallidaceae Traub, Hyacinthaceae Batsch ex Borkh., Laxmanniaceae Bubani, Ruscaceae M.Roem. [which includes Convallariaceae] and Themidaceae Salisb.) Family Asphodelaceae Juss. (including Hemerocallidaceae R.Br. and Xanthorrhoeaceae Dumort)The name Xanthorrhoeaceae has priority , but Asphodelaceae has been proposed for conservation and is used in anticipation in the APG IV system of classification. Family Asteliaceae Dumort. Family Blandfordiaceae R. Dahlgren & Clifford Family Boryaceae M.W. Chase, Rudall & Conran Family Doryanthaceae R. Dahlgren & Clifford Family Hypoxidaceae R.Br. Family Iridaceae Juss. Family Ixioliriaceae Nakai Family Lanariaceae R. Dahlgren & A.E.van Wyk Family Orchidaceae Juss. Family Tecophilaeaceae Leyb. Family Xeronemataceae M.W. Chase, Rudall & M.F.Fay

The earlier 2003 version, APG II, allowed 'bracketed' families, i.e. families which could either be segregated from more comprehensive families or could be included in them. These are the families given under "including" in the list above. APG III does not allow bracketed families, requiring the use of the more comprehensive family; otherwise the circumscription of the Asparagales is unchanged. A separate paper accompanying the publication of the 2009 APG III system provided subfamilies to accommodate the families which were discontinued. The first APG system of 1998 contained some extra families, included in square brackets in the list above.

Comparison with older systems Two older systems which use the order Asparagales are the Dahlgren system and the Kubitzki system. The families included in the circumscriptions of the order in these are wrong info

+ Families included in Asparagales in three systems which use this order Dahlgren system Kubitzki system APG IV system – Agapanthaceae Amaryllidaceae: Agapanthoideae Agavaceae Asparagaceae: Agavoideae Alliaceae Amaryllidaceae: Allioideae Amaryllidaceae Amaryllidaceae: Amaryllidoideae – Anemarrhenaceae Asparagaceae: Agavoideae Anthericaceae Asparagaceae: Agavoideae Aphyllanthaceae Asparagaceae: Aphyllanthoideae Asparagaceae Asparagaceae: Asparagoideae Asphodelaceae Asphodelaceae: Asphodeloideae Asteliaceae Asteliaceae – Behniaceae Asparagaceae: Agavoideae Blandfordiaceae Blandfordiaceae – Boryaceae Boryaceae Calectasiaceae — Not in Asparagales (family Dasypogonaceae, unplaced as to order, clade commelinids) Convallariaceae Asparagaceae: Convallarioideae Cyanastraceae – Tecophilaeaceae Dasypogonaceae – Not in Asparagales (family Dasypogonaceae, unplaced as to order, clade commelinids) Doryanthaceae Doryanthaceae Dracaenaceae Asparagaceae: Convallarioideae Eriospermaceae Asparagaceae: Convallarioideae Hemerocallidaceae Asphodelaceae: Hemerocallidoideae Herreriaceae Asparagaceae: Agavoideae Hostaceae Asparagaceae: Agavoideae Hyacinthaceae Asparagaceae: Scilloideae Hypoxidaceae Hypoxidaceae – Iridaceae Iridaceae Ixioliriaceae Ixioliriaceae – Johnsoniaceae Asphodelaceae: Hemerocallidoideae Lanariaceae Lanariaceae Luzuriagaceae – Not in Asparagales (family Alstroemeriaceae, order Liliales) – Lomandraceae Asparagaceae: Lomandroideae Nolinaceae Asparagaceae: Convallarioideae – Orchidaceae Orchidaceae Philesiaceae – Not in Asparagales (family Philesiaceae, order Liliales) Phormiaceae – Asphodelaceae: Hemerocallidoideae Ruscaceae Asparagaceae: Convallarioideae Tecophilaeaceae Tecophilaeaceae – Themidaceae Asparagaceae: Brodiaeoideae Xanthorrhoeaceae Asphodelaceae: Xanthorrhoeoideae

Descriptions of families and subfamilies

Orchidaceae

The orchid family is one of the two largest families of angiosperms (the other is Asteraceae). The shape of the flowers is very distinctive, making orchids easy to recognize. The flower is bilaterally symmetrical. The three sepals are generally colourful and bright (which is why they are sometimes called outer tepals), with one on each side ("lateral sepals") and one usually at the top of the flower ("dorsal sepal"), sometimes forming a hood. The three petals (or inner tepals), also showy, are located alternately between the sepals, two at the side and one usually at the bottom of the flower. The lower petal is referred to as the "labellum" or "lip", and is usually distinctively different from the side petals. Thelymitra is an example of a genus where the lower petal is similar in appearance to the other petals. The pollination systems of orchids are among the most complex and interesting of all the angiosperms. Orchids include many species of great ornamental value. Vanilla is obtained from the fruit of the orchid Vanilla planifolia.

Boryaceae

The genus Borya contains tree-like species which behave as "resurrection plants". Growing on rocky slopes, the plants dry out during the dry season and become a rusty orange color, but quickly turn green and become active again once it starts to rain. Along with the other genus in the family Boryaceae, Alania, these xerophytic plants are native to Australia.

Blandfordiaceae

Blandfordia is the only genus in the family Blandfordiaceae, with four species distributed in eastern Australia. They are commonly called "Christmas bells", because of the shape of their flowers and their flowering time, which coincides with Christmas in Australia. They are upright perennial herbs (to about 1.50 m), with distinctive leaves. The inflorescence is a raceme. Individual flowers have jointed pedicels and tepals forming a tubular shape. The seeds have conspicuous hairs.

Lanariaceae

Lanaria lanata is the only species in the family Lanariaceae and is found in southern South Africa. A more or less typical monocotyledon, the species can be recognized by its shortly branched inflorescence covered with branched hairs (giving rise to the common name of Lamb's-tail). The flowers are radially symmetrical.

Asteliaceae

The Asteliaceae is a family of two to four genera of plants found in the Southern Hemisphere. They are more or less rhizomatous, with spiral leaves and an inflorescence that may form a raceme or a spike. There are large bracts at the base of the inflorescence. The individual flowers are small, with tepals joined at the base.

Hypoxidaceae

The family includes some 150 species with a worldwide distribution, excluding Europe and northern Asia. Species can be recognized by their rosettes of more or less folded leaves with persistent bases and quite prominent nonglandular hairs. The tepals in the outer whorl tend to be green on the outside. The ovary is inferior with often a thin tubular portion at its apex formed by joined tepals or the tip of the ovary.

Ixioliriaceae

The family includes a single genus, Ixiolirion, with four species distributed from Egypt to central Asia. They are herbs with corms and an inflorescence forming a cluster. The individual flowers are blue, shortly tubular, with an inferior ovary.

Tecophilaeaceae

The nine genera are found in Chile, the United States and Africa. They are herbs with corms and leaves which are sometimes stalked (petiolate) with wide blades. The flowers have tepals that open outwards. The stamens are strongly dimorphic. The anthers open by pores. The genus Cyanastrum is sometimes placed in its own family Cyanastraceae.

Doryanthaceae

The two species of Doryanthes, the only genus of the family, are huge rosette-forming herbs that are a conspicuous element of the flora in the vicinity of Sydney, being hard not to notice when in flower. The leaves have entire margins but disintegrate into fibres at the apex. The sub-umbellate inflorescences are borne at the end of long stems, having numerous bright red flowers, which are radially symmetric with inferior ovaries.

Iridaceae

The iris family contains about 70 genera and over 1,600 species with a worldwide distribution. Members of the family are usually perennial herbs with sword-shaped unifacial leaves; the inflorescence is a spike or panicle of solitary flowers, or forms a monochasial cyme or rhipidium (meaning that the successive stems of the flowers follow a zig-zag path in the same plane); and the flower has only three stamens, each opposite to an outer tepal. Saffron is obtained from the dried styles of Crocus sativus L., a member of the iris family. The corms of some species of Iridaceae are used as food by some indigenous peoples. Many species in the iris family have a great economic importance in ornamental horticulture and the cut flower industry, especially Gladiolus, Freesia, Sparaxis, Iris, Tigridia (tiger lily), Ixia (corn lily), Romulea, Neomarica, Moraea (butterfly lily), Nemastylis, Belamcanda, Sisyrinchium (blue-eyed grass), Crocosmia and Trimezia. Many other genera, both perennials and bulbs, are grown in gardens in tropical and temperate regions (e.g. Watsonia, Crocus, Dietes, Tritonia, Hesperantha and Neomarica). Moraea and Homeria are two genera of poisonous plants which are a problem in sheep and cattle producing regions, notably in South Africa.

Xeronemataceae

The family consists of a single genus Xeronema with two species, one found only on the Poor Knights islands in New Zealand and the other in New Caledonia. The inflorescence is crowded with quite large, radial symmetrical flowers, which face upwards. The stamens are strongly exserted (i.e. extend out of the flower). The family is still poorly known.

Asphodelaceae sensu lato