Dorotheantheae
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Dorotheantheae is a small
tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...
of
annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year **Yearbook **Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), a ...
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 ...
in the
Aizoaceae The Aizoaceae (), or fig-marigold family, is a large family of dicotyledonous flowering plants containing 135 genera and about 1,800 species. Several genera are commonly known as 'ice plants' or 'carpet weeds'. The Aizoaceae are also referred to a ...
subfamily Ruschioideae. Though it originally comprised three
genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...
(''Aethephyllum'', ''
Cleretum ''Cleretum'' is a genus of flowering plants in the family Aizoaceae, native to the Cape Provinces of South Africa. Taxonomy The genus ''Cleretum'' was erected by Nicholas Edward Brown in 1925. He published the name in a key, basing the diagnosis ...
'', and ''Dorotheanthus),'' ''Cleretum'' remains as the only recognised genus. Dorotheantheae are
endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to the western and south-western parts of
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
. The
type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...
is ''Dorotheanthus'', despite it being no longer recognised.


Distribution and description

Species in the Dorotheantheae tribe are
endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to the south and southwest areas of
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
, specifically the
Cape Floristic Region The Cape Floral Region is a floristic region located near the southern tip of South Africa. It is the only floristic region of the Cape Floristic Kingdom, and includes only one floristic province, known as the Cape Floristic Province. The Cap ...
and Succulent Karoo Region, or "Greater Cape Flora", an area that sees great diversity in its flora, though, remains distinct. In turn, this means the location of individual species can range from as north as
Namaqualand Namaqualand ( Khoikhoi: "Nama-kwa" meaning Nama Khoi people's land) is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of . It is divided by the lower course of the Orange River int ...
to as east as
Plettenberg Bay Plettenberg Bay, nicknamed Plett, is the primary town of the Bitou Local Municipality in the Western Cape Province of South Africa. According to the census of 2001, the town had a population of 29,149. It was originally named Bahia Formosa ("Be ...
. The species most commonly appear in flat and open areas, occasionally with the land consisting of
loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–si ...
or sand. All species are
annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year **Yearbook **Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), a ...
succulent 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'', meani ...
herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...
s. The difference in appearance between each of the tribe's four formerly recognised
clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
s is usually minor. The leaf shape is
spathulate This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary ...
, with the exception of those that were members of the '' Aethephyllum'' clade, with those having
lyrate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...
leaves. All species have visible bladder cells, typically described as "moderately raised". The
pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...
is either long or short and there is distinct variation between clades for the vibrancy and colouration of the flower and its conspicuousness. Additionally, the diameter of the flower ranges from large to small. All species have papillate seed surfaces, besides those that were in the ''
Dorotheanthus ''Cleretum'' is a genus of flowering plants in the family Aizoaceae, native to the Cape Provinces of South Africa. Taxonomy The genus ''Cleretum'' was erected by N. E. Brown, Nicholas Edward Brown in 1925. He published the name in a key, basing ...
'' subg. ''Dorotheanthus'' clade.


Genera

There is only one recognised genus in the Dorotheantheae tribe, per
Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...
: * ''
Cleretum ''Cleretum'' is a genus of flowering plants in the family Aizoaceae, native to the Cape Provinces of South Africa. Taxonomy The genus ''Cleretum'' was erected by Nicholas Edward Brown in 1925. He published the name in a key, basing the diagnosis ...
''
N.E.Br. Nicholas Edward Brown (11 July 1849 in Redhill, Surrey – 25 November 1934 in Kew Gardens, London) was an English plant taxonomist and authority on succulents. He was also an authority on several families of plants, including Asclepiadaceae, ...
Previously, another two genera were recognised as being members of this tribe: * ''Aethephyllum'' N.E.Br. * ''Dorotheanthus'' Schwantes (the
type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...
) In a molecular study completed by Cornelia Klak and Peter V. Bruyns in 2012 and published in the scientific journal ''
Taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...
'', titled "Phylogeny of the Dorotheantheae (Aizoaceae), a tribe of succulent annuals", it was found that Dorotheantheae consisted of four clades: the aforementioned three modified to have ''Dorotheanthus'' split in two, introducing ''D.'' subg. ''Dorotheanthus'' and ''D.'' subg. '' Pherolobus''. Additionally, it was proved that the genus ''Cleretum'' was not
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 ...
, as
circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...
in 1987, and hence some species were better suited under the genus ''Aethephyllum''. Following this, it was argued that "fruit morphology" was unreliable for discerning genera in the family
Aizoaceae The Aizoaceae (), or fig-marigold family, is a large family of dicotyledonous flowering plants containing 135 genera and about 1,800 species. Several genera are commonly known as 'ice plants' or 'carpet weeds'. The Aizoaceae are also referred to a ...
; the most common manner was to consider combinations of homoplasious characteristics. This method was considered by Klak and Bruyns to be "not necessarily justified", with it being the only differentiating factor between the ''Cleretum'' and ''Dorotheanthus'' clades. Hence, despite there being aspects allowing for the recognition of ''Dorotheanthus'' and ''Aethephyllum'', though they "remain ddifficult to distinguish", the conclusions of the study were that while the tribe is adequately characterised, the factors differentiating each genus are indistinct or negligible and should be reduced to only ''Cleretum'' due to that species' loose circumscription. Prior to the study, the genera ''Cleretum'' and ''Dorotheanthus'' were often confused, as noted in the "Aizoaceae A-E" edition of
Heidrun Hartmann Heidrun Hartmann (; 5 August 1942, Kolberg – 11 July 2016) was a German botanist. She worked at the University of Hamburg and specialised in Aizoaceae, Crassulaceae The Crassulaceae (, from Latin ''crassus'', thick), also known as the crass ...
's 2001 book "Illustrated Handbook of Succulent Plants".


References


External links

* * {{Taxonbar, from=Q5813604 Aizoaceae Caryophyllales tribes Monotypic plant taxa