Asphodeloideae is a subfamily of the

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of t ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...

Asphodelaceae in the order

Asparagales Asparagales (asparagoid lilies) is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group (APG) and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in ...

. 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 particul ...

''. 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

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial no ...

, '' Asphodelus''. Members of group are

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entertai ...

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

, central and western

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, the

Mediterranean basin In biogeography, the Mediterranean Basin (; also known as the Mediterranean Region or sometimes Mediterranea) is the region of lands around the Mediterranean Sea that have mostly a Mediterranean climate, with mild to cool, rainy winters and wa ...

, Central

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

and

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country b ...

, with one

(''

Bulbinella ''Bulbinella'' is a genus of plants in the family Asphodelaceae, subfamily Asphodeloideae,Stevens, P.F. (2001 onwards)"Asphodeloideae" ''Angiosperm Phylogeny Website''. Retrieved 2016-06-10. first described as a genus in 1843. Many species are en ...

'') having some of its

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island country ...

. The greatest diversity occurs in

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

. The genera ''

Aloe ''Aloe'' (; also written ''Aloë'') is a genus containing over 650 species of flowering succulent plants.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Accessed on: 06 Nov 2022 The most wi ...

'', '' Asphodelus'', and '' Kniphofia'' are perhaps best known from their use in horticulture as

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

Description

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

microsporogenesis Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametoph ...

, 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 megasporangium), and the ...

s morphology, and the presence of an

aril An aril (pronounced ), also called an 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 se ...

. 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 The meristem is a type of tissue found in plants. It consists of undifferentiated cells (meristematic cells) capable of cell division. Cells in the meristem can develop into all the other tissues and organs that occur in plants. These cells conti ...

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

, including

Agavaceae Agavoideae is a subfamily of monocot flowering plants in the family Asparagaceae, order Asparagales. It has previously been treated as a separate family, Agavaceae. The group includes many well-known desert and dry-zone types, such as the agav ...

Iridaceae Iridaceae is a family of plants in order Asparagales, taking its name from the irises, meaning rainbow, referring to its many colours. There are 66 accepted genera with a total of c. 2244 species worldwide (Christenhusz & Byng 2016). It include ...

, and

Xanthorrhoeoideae ''Xanthorrhoea'' () is a genus of about 30 species of flowering plants endemic to Australia. Species are known by the name grass tree. Description All are perennials and have a secondary thickening meristem in the stem. Many, but not all, ...

. It is confined to

among the

monocots Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of t ...

and is believed to have evolved independently in most families.

Aloin cells

The presence of aloin 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 Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word ...

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 i ...

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 inc ...

. Chase posits that they are involved in

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

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 organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoan ...

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 als ...

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 Asphodelaceae, the Aloinaceae. Other taxonomists have subsequently

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every pol ...

a tribe, Aloineae (or Aloeae) to include '' Gasteria'', '' Haworthia'' 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 cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

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 within the subfamily Asphodeloideae by those adopting the broad APG IV system circumscription 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'', mea ...

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

, while the other genera have mainly a

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

n distribution.

Aloeae

, Aloeae (or Alooideae s.s.) comprises ''

'', '' Aloiampelos'', '' Aloidendron'', '' Aristaloe'', '' Astroloba'', '' Gasteria'', '' Gonialoe'', '' Haworthia'', ''

Haworthiopsis ''Haworthiopsis'' is a genus of succulent plants in the subfamily Asphodeloideae. The genus was previously included in '' Haworthia''. Species in the genus are typically short perennial plants, with leaves often arranged in a rosette and frequ ...

'', '' Kumara'' and ''

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

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

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

. Evidence for

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of Aloeae is based on distinctive

karyotype A karyotype is the general appearance of the complete set of metaphase 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 dis ...

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 Outgroup may refer to: * Outgroup (cladistics) In cladistics or phylogenetics, an outgroup is a more distantly related group of organisms that serves as a reference group when determining the evolutionary relationships of the ingroup, the set of o ...

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, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx ( sepals) and the corolla ( petals) or tepals wh ...

segments, but it lacks succulent leaves.

Selected list of genera

The genera listed below are those accepted by APWeb . 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. *'' Asphodelus'' L. *'' Bulbine'' Wolf *''

'' Kunth *'' Chortolirion'' A.Berger *'' Eremurus'' M.Bieb. *'' Gasteria'' Duval *'' Gonialoe'' (Baker) Boatwr. & J.C.Manning *'' Haworthia'' Duval *''

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

'' Raf. For a

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological sp ...

of the family, see the

phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological sp ...

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

in L. Watson and M.J. Dallwitz (1992 onwards).
The families of flowering plants
descriptions, illustrations, identification, information retrieval.'' Version: 9 March 2006. https://web.archive.org/web/20070103200438/http://delta-intkey.com/
NCBI Taxonomy Browser

links at CSDL, Texas

External links

{{Authority control Asparagales subfamilies