Asphodeloideae is a subfamily of the

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are flowering plants whose seeds contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Asphodelaceae Asphodelaceae is a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription has varied widely. In its current circumscription in the APG IV system, it includes about 4 ...

in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Asparagales Asparagales (asparagoid lilies) are a diverse order of flowering plants in the monocots. Under the APG IV system of flowering plant classification, Asparagales are the largest order of monocots with 14 families, 1,122 genera, and about 36,00 ...

. It has previously been treated as a separate family, Asphodelaceae ''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

''. The family Asphodelaceae has now been proposed to be a nomen conservandum, and the proposal has been recommended for ratification in 2017. In that case, Asphodelaceae will have priority over Xanthorrhoeaceae. This is reflected in the APG IV family lists. The subfamily name is derived from the generic name of the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

, ''

Asphodelus ''Asphodelus'' is a genus of mainly perennial flowering plants in the asphodel family Asphodelaceae that was first described by Carl Linnaeus in 1753. The genus was formerly included in the lily family (Liliaceae). The genus is native to temper ...

''. Members of this group can be found growing

native Native may refer to: People * '' Jus sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...

in coastal

Southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...

, Central and

Western Europe Western Europe is the western region of Europe. The region's extent varies depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the Western half of the ancient Mediterranean ...

, the Mediterranean basin,

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

; one

, '' Bulbinella'', can additionally be found growing in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. The greatest

diversity Diversity, diversify, or diverse may refer to: Business *Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce *Diversity marketing, marketing communication targeting diverse customers * ...

occurs in South Africa. Several genera, notably ''

Aloe ''Aloe'' (; also written ''Aloë'') is a genus containing over 650 species of flowering plant, flowering succulent plant, succulent plants.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Acc ...

'', ''

Gasteria ''Gasteria'' is a genus of succulent plants, native to South Africa and the far south-west corner of Namibia. Naming The genus is named for its stomach-shaped flowers (''"gaster"'' is Greek for "stomach") that result from the swollen base on the ...

'', ''

Haworthia ''Haworthia'' is a large genus of small succulent plants endemic to Southern Africa (Mozambique, Namibia, Lesotho, Eswatini and South Africa). Like aloes and gasteria they are members of the Family (biology), subfamily Asphodeloideae and they ...

'' and '' Kniphofia'' are perhaps the best known of the family due to their use among plant collectors, botanists and horticulturists. Additional genera and hybrids are also known, including '' Aristaloe'', '' Gasteraloe'' and '' Gonialoe'' (the latter formerly included the now-rehomed Aloe variegata, or partridge-breast aloe). Eremurus stenophyllus0

Description

The Asphodeloideae are distinguished by a general presence of anthraquinones, simultaneous microsporogenesis, atypical

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the sporangium, megasporangium), ...

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

, and the presence of an

aril An aril (), also called arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode, or false aril, is sometimes distinguished: whereas an aril grows from the attachment point of the seed to the ova ...

. Asphodeloideae also have a characteristic

secondary growth In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips ...

by means of a secondary thickening

meristem In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic c ...

. This character, however, is also found in other taxa in the

, including Agavaceae,

Iridaceae Iridaceae () is a family of plants in order Asparagales, taking its name from the Iris (plant), irises. It has a nearly global distribution, with 69 accepted genera with a total of about 2500 species. It includes a number of economically importan ...

, and Xanthorrhoeoideae. It is confined to

among the

monocots Monocotyledons (), commonly referred to as monocots, ( Lilianae '' sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks a ...

and is believed to have evolved independently in most families.

Aloin cells

The presence of

aloin Aloin, also known as barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 ''Aloe'' species at levels from 0.1 to 6.6% of leaf dry weight (making between 3% and 35% of the total exudate), and in another 17 spec ...

cells is a distinctive character of the Aloeae. These cells are present in all Aloeae, but are absent in most of the other genera within Asphodeloideae. A well-developed cap of thin-walled

parenchyma upright=1.6, Lung parenchyma showing damage due to large subpleural bullae. Parenchyma () is the bulk of functional substance in an animal organ such as the brain or lungs, or a structure such as a tumour. In zoology, it is the tissue that ...

cells occurs at the

phloem Phloem (, ) is the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This transport process is ...

pole of each

vascular bundle A vascular bundle is a part of the transport system in vascular plants. The transport itself happens in the stem, which exists in two forms: xylem and phloem. Both these tissues are present in a vascular bundle, which in addition will incl ...

. Chase posits that they are involved in

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

production, but Beaumont suggests that the cells act as a storage tissue for compounds synthesized in the surrounding layer of cells. The aloin cells are said to produce the characteristic thick exudate that is produced when the succulent leaf of aloe is severed. The aloin cells produce

anthraquinone Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic hydrocarbon, aromatic organic compound with formula . Several isomers exist but these terms usually refer to 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein th ...

and

chromone Chromone (or 1,4-benzopyrone) is a derivative of benzopyran with a substituted keto group on the pyran ring. It is an isomer of coumarin. Derivatives of chromone are collectively known as ''chromones''. Most, though not all, chromones are also ...

derivatives, which may be responsible for the medicinal attributes of ''

''.

Taxonomy

Lotsy (1911) placed a number of genera ('' Kniphofia'', '' Notosceptrum'', '' Chortolirion'' and ''

'') into a family, separate from

, the Aloinaceae. Other taxonomists have subsequently circumscribed a tribe, Aloineae (or Aloeae) to include ''

'', ''

'' and ''Aloe''. Other taxonomic terms have included Aloaceae, Alooideae, Aloideae, Aloidea, Aloides, Aloinae and Aloeace, with the type genus ''Aloe''.

Phylogeny of Asphodeloideae

There is agreement among many researchers that Asphodeloideae can be further divided into a

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

group comprising ''Aloe'' and its immediate relatives, and a nonmonophyletic group of the remaining genera. The monophyletic group can be treated as the tribe

Aloeae Aloeae is a tribe of succulent plants in the subfamily Asphodeloideae of the family Asphodelaceae, consisting of the aloes and their close relatives. The taxon may also be treated as the subfamily Alooideae by those botanists who retain the narr ...

within the subfamily Asphodeloideae by those adopting the broad

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...

circumscription Circumscription may refer to: * Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthr ...

of the Asphodelaceae. (Alternatively, it may be treated as the subfamily Alooideae within a more narrowly circumscribed family Asphodelaceae.) Aloeae are mainly rosulated-leaf

succulents In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meanin ...

, while the other genera are not succulent. The genera in Aloeae are centered in southern

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, while the other genera have mainly a

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

n distribution.

Aloeae

(or Alooideae s.s.) comprises ''

'', '' Aloiampelos'', '' Aloidendron'', '' Aristaloe'', '' Astroloba'', ''

'', '' Gonialoe'', ''

'', '' Haworthiopsis'', '' Kumara'' and ''

Tulista ''Tulista'' is a small genus of succulent plants endemic to the Cape Provinces of South Africa. They were formerly included within the genus ''Haworthia''. Characteristics The genus is characterised by a large size (relative to other haworthias) ...

''. The genera within Alooideae have several morphological characters that can be distinguished in the field, namely the arrangement and type of leaf and

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

. Evidence for

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

of Aloeae is based on distinctive

karyotype A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by de ...

and characteristic leaf morphology. The '' Bulbine'' group has characteristics of Aloeae, but is not included in the group due to a lack of tubular flowers. '' Kniphofia'' is considered an outgroup of Aloeae since it has tubular flowers and a fusion of

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower. It is a structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepal ...

segments, but it lacks succulent leaves.

Selected list of genera

The genera listed below are those accepted by

APWeb The Angiosperm Phylogeny Website (or APweb) is a website that presents up-to-date research on the phylogeny and taxonomy of flowering plants (angiosperms) in what is intended to be a user-friendly way. The site is hosted by the Missouri Botanical ...

. Other treatments combine some of these genera into as few as seven. * ''

'' L. * '' Aloiampelos'' Klopper & Gideon F.Sm. * '' Aloidendron'' (A.Berger) Klopper & Gideon F.Sm. * '' Aristaloe'' Boatwr. & Manning * '' Astroloba'' Uitewaal * '' Asphodeline'' Rchb. * ''

'' L. * '' Bulbine'' Wolf * '' Bulbinella'' Kunth * '' Chortolirion'' A.Berger * '' Eremurus'' M.Bieb. * ''

'' Duval * '' Gonialoe'' (Baker) Boatwr. & J.C.Manning * ''

'' Duval * '' Haworthiopsis'' G.D.Rowley * '' Jodrellia'' Baijnath * '' Kniphofia'' Moench * '' Kumara'' Medik * '' Trachyandra'' Kunth * ''

'' Raf. For a

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

of the family, see the phylogenetic tree at Asphodelaceae.Dion S. Devey, Ilia Leitch, Paula J. Rudall, J. Chris Pires, Yohan Pillon, and Mark W. Chase. "Systematics of Xanthorrhoeaceae sensu lato, with an emphasis on ''Bulbine''". ''Aliso'' 22(''Monocots: Comparative Biology and Evolution''):345-351. ISSN 0065-6275.

References

Bibliography

* * *
Asphodeloideae
At

At
Missouri Botanical Garden Website

Asphodelaceae
in L. Watson and M.J. Dallwitz (1992 onwards).
The families of flowering plants
descriptions, illustrations, identification, information retrieval.'' Version: 9 March 2006.
NCBI Taxonomy Browser

links at CSDL, Texas

External links

{{Authority control Asparagales subfamilies