Hemerocallidaceae
Encyclopedia
Hemerocallidoideae is the botanical name
Botanical name
A botanical name is a formal scientific name conforming to the International Code of Botanical Nomenclature and, if it concerns a plant cultigen, the additional cultivar and/or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants...

 of a subfamily of flowering plants, part of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Xanthorrhoeaceae
Xanthorrhoeaceae
Xanthorrhoeaceae is the botanical name of a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription of the family has varied wildly....

 sensu lato in the monocot  order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Asparagales
Asparagales
Asparagales is the name of an order of plants, used in modern classification systems such as the APG III system . The order takes its name from the family Asparagaceae and is placed in the monocots. The order has only recently been recognized in classification systems...

 according to the APG
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...

 system of 2009
APG III system
The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...

. Earlier classification systems treated the group as a separate family, the Hemerocallidaceae. The name is derived from the generic name
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...

 of the type
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...

 genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

, Hemerocallis. The largest genera in the group
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 are Dianella (with 20 species), Hemerocallis (15), and Caesia
Caesia
Caesia is a genus of herbs in the family Hemerocallidaceae, native to Australia, New Guinea and Southern Africa. The mostly 3-lobed seed capsules contain rounded black seeds.Species include*Caesia alpina Hook.f. - Alpine Grass-Lily...

 (11).

In the 21st century, the group has had two basic forms, depending on whether Johnsonia and its relatives are included or not. Each of these forms can vary by the inclusion or exclusion of Xeronema
Xeronema
Xeronema is a genus of flowering plants containing two species:* The Poor Knights lily is endemic to the Poor Knights Islands and Taranga Island in the north of New Zealand. It was discovered in 1924. The Poor Knights lily has large bottlebrush flower clusters that grow horizontally. The clusters...

. If defined narrowly, most of the group are native
Indigenous (ecology)
In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...

 to tropical and temperate Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

 and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. They also occur in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, many Pacific islands
Pacific Islands
The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....

, western South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, and Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

, but not in Sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...

 or North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. If defined broadly, then the group includes the genus Caesia
Caesia
Caesia is a genus of herbs in the family Hemerocallidaceae, native to Australia, New Guinea and Southern Africa. The mostly 3-lobed seed capsules contain rounded black seeds.Species include*Caesia alpina Hook.f. - Alpine Grass-Lily...

, which is indigenous to Southern Africa
Southern Africa
Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN...

, as well as Australia.

The APG III system
APG III system
The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...

 of 2009 uses the broader definition of the group, treating it as the subfamily Hemerocallidoideae of the family Xanthorrhoeaceae sensu lato.

Hemerocallis fulva
Hemerocallis fulva
Hemerocallis fulva is a species of Hemerocallis, native to Asia from the Caucasus east through the Himalaya to China, Japan, Korea, and southeastern Russia.-Growth:...

 is a common ornamental
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...

. Other species of Hemerocallis are cultivated
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...

 as well. Hemerocallis citrina has medicinal uses. Phormium tenax
Phormium tenax
Phormium tenax is an evergreen perennial plant native to New Zealand and Norfolk Island that is an important fibre plant and a popular ornamental plant...

 is a source of fiber
Fiber
Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....

 in New Zealand.

Circumscription

Some of the older systems included Xeronema
Xeronema
Xeronema is a genus of flowering plants containing two species:* The Poor Knights lily is endemic to the Poor Knights Islands and Taranga Island in the north of New Zealand. It was discovered in 1924. The Poor Knights lily has large bottlebrush flower clusters that grow horizontally. The clusters...

 in Hemerocallidaceae, but with considerable doubt about whether it really belonged there. Molecular phylogenetic studies
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

 of DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...

s have shown that Xeronema
Xeronema
Xeronema is a genus of flowering plants containing two species:* The Poor Knights lily is endemic to the Poor Knights Islands and Taranga Island in the north of New Zealand. It was discovered in 1924. The Poor Knights lily has large bottlebrush flower clusters that grow horizontally. The clusters...

 is sister to a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 consisting of Xanthorrhoeaceae
Xanthorrhoeaceae
Xanthorrhoeaceae is the botanical name of a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription of the family has varied wildly....

 sensu lato, Amaryllidaceae
Amaryllidaceae
Amaryllidoideae is the subfamily of flowering plants that takes its name from the genus Amaryllis. It is part of the family Amaryllidaceae, in order Asparagales...

 sensu lato, and Asparagaceae
Asparagaceae
Asparagaceae is the botanical name of a family of flowering plants, placed in the order Asparagales of the monocots.In earlier classification systems, the species involved were often treated as belonging to the family Liliaceae...

 sensu lato. Xeronema is now placed in its own family, Xeronemataceae
Xeronemataceae
Xeronemataceae is the botanical name of a family of flowering plants, placed in the order Asparagales of the monocots.The name was published in 2000 and has therefore been recognized only in recent taxonomies...

.

In 1985, Dahlgren
Rolf Dahlgren
Rolf Martin Theodor Dahlgren was a Swedish-Danish botanist, professor at the University of Copenhagen from 1973 to his death....

, Clifford, and Yeo produced a work on monocot taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 that remained influential for over two decades. They defined Hemerocallidaceae as consisting only of Hemerocallis. They excluded Phormium and its relatives, placing them into a separate family, Phormiaceae. This treatment was followed by Armen Takhtajan
Armen Takhtajan
Armen Leonovich Takhtajan or Takhtajian , was a Soviet-Armenian botanist, one of the most important figures in 20th century plant evolution and systematics and biogeography. His other interests included morphology of flowering plants, paleobotany, and the flora of the Caucasus...

 in 2009, in a classification that was based almost entirely on morphology
Plant morphology
Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level...

 and that recognized paraphyletic groups. It was not followed in a major work on monocot taxonomy which appeared in 1998.

In the 21st century, Hemerocallidaceae has been defined in essentially two different ways in systems based on monophyletic groups. In the narrower of these circumscriptions
Circumscription (taxonomy)
In taxonomy, circumscription is the definition of the limits of a taxonomic group of organisms. One goal of taxonomy is to achieve a stable circumscription for every taxonomic group. Achieving stability can be simple or difficult....

, Hemerocallidaceae sensu stricto, it consists of 12 genera and 40 to 50 species. It does not include the 8 genera and about 38 species that are placed in a separate family, Johnsoniaceae.

The broader version of the family, Hemerocallidaceae sensu lato, includes those species that would otherwise be assigned to Johnsoniaceae. Johnsoniaceae and Hemerocallidaceae sensu stricto form a clade that has strong statistical support
Resampling (statistics)
In statistics, resampling is any of a variety of methods for doing one of the following:# Estimating the precision of sample statistics by using subsets of available data or drawing randomly with replacement from a set of data points # Exchanging labels on data points when performing significance...

. One study found Johnsoniaceae to be embedded
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...

 in Hemerocallidaceae sensu stricto, but this result did not have strong bootstrap
Bootstrapping (statistics)
In statistics, bootstrapping is a computer-based method for assigning measures of accuracy to sample estimates . This technique allows estimation of the sample distribution of almost any statistic using only very simple methods...

 support.

The broader version of Hemerocallidaceae is the one that was accepted by the Angiosperm Phylogeny Group
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...

 when they published the APG II system
APG II system
The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...

 in 2003. When this system was superseded by APG III in 2009, Hemerocallidaceae was not recognized, instead being treated as subfamily Hemerocallidoideae of the expanded family Xanthorrhoeaceae sensu lato.

For a phylogeny of Hemerocallidaceae, see the phylogenetic tree
Phylogenetic tree
A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...

 at Xanthorrhoeaceae
Xanthorrhoeaceae
Xanthorrhoeaceae is the botanical name of a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription of the family has varied wildly....

.

Genera

As noted above, a broad circumscription of the group includes the two former families Hemerocallidaceae sensu stricto and Johnsoniaceae. The Kubitzki system of 1998 has 12 genera (not counting Xeronema) in Hemerocallidaceae and eight genera in Johnsoniaceae. These are listed below. Some authors combine some of the more closely related genera, recognizing as few as three genera in Hemerocallidaceae sensu stricto and as few as one in Johnsoniaceae.
  • Agrostocrinum F.Mueller
  • Arnocrinum Endlicher & Lehmann
  • Caesia
    Caesia
    Caesia is a genus of herbs in the family Hemerocallidaceae, native to Australia, New Guinea and Southern Africa. The mostly 3-lobed seed capsules contain rounded black seeds.Species include*Caesia alpina Hook.f. - Alpine Grass-Lily...

     R.Br.
  • Corynotheca Benth.
  • Dianella Lamarck
  • Eccremis Baker
  • Geitonoplesium R.Br.
  • Hemerocallis L.
  • Hensmania W.Fitzgerald
  • Herpolirion
    Herpolirion
    Herpolirion is a genus of perennial herbs in the family Xanthorrhoeaceae, subfamily Hemerocallidoideae. The sole species is Herpolirion novae-zelandiae, commonly known as Sky Lily...

     Hook.f.
  • Hodgsoniola F.Muell.
  • Johnsonia R.Br.
  • Pasithea D.Don
  • Phormium J.R.Forst. & G.Forst.
  • Rhuacophila Blume
  • Stypandra
    Stypandra
    Stypandra is a small genus of rhizomatous perennials in the family family Xanthorrhoeaceae, subfamily Hemerocallidoideae. They are native to Australia and New Caledonia.Species include:*Stypandra glauca R.Br....

     R.Br.
  • Simethis Kunth
  • Stawellia F.Muell.
  • Thelionema
    Thelionema
    Thelionema is a small genus of tufted perennials in the family Xanthorrhoeaceae, subfamily Hemerocallidoideae. All three species, which were previously placed in the genus Stypandra, are native to Australia. These are:...

     R.J.F.Hend.
  • Tricoryne
    Tricoryne
    Tricoryne is a genus of perennial herbs in the family Xanthorrhoeaceae, subfamily Hemerocallidoideae. All species are native to Australia with one extending to New Guinea; within Australia they occur in all mainland states except the Northern Territory....

    R.Br.

External links


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