''Corymbium'' is a
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 n ...
of flowering plants in the
daisy family
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
comprising nine species. It is the only genus in the subfamily Corymbioideae and the tribe Corymbieae.
The species have leaves with parallel veins, strongly reminiscent of monocots, in a rosette and compounded inflorescences may be compact or loosely composed
raceme
A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the sh ...
s,
panicle
A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is ...
s or
corymb
Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficia ...
s. Remarkable for species in the daisy family, each flower head contains just one, bisexual, mauve, pink or white disc floret within a sheath consisting of just two large involucral bracts.
The species are all
endemic
Endemism is the state of a species being found 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 found els ...
to the
Cape Floristic Region of
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 count ...
, where they are known as plampers.
[
]
Description
The species of ''Corymbium'' are monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy.
Monoecy i ...
, stemless, perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
, herbaceous plant
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.
Definitions of "herb" and "herbaceous"
The fourth edition ...
s of high, that grow in tufts and look like a monocotyledon
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 ...
as long as they are not flowering. The plants have a fibrous rhizome that is covered the persisting bases of old leaves and long, soft, silky hairs. Most parts of the plants may be covered in long soft hairs, or coarse hairs or lack indumentum
In biology, an indumentum (Latin, literally: "garment") is a covering of trichomes (fine "hairs") on a plantDavis, Peter Hadland and Heywood, Vernon Hilton (1963) ''Principles of angiosperm taxonomy'' Van Nostrandpage, Princeton, New Jersey, page ...
. All leaves are in a basal rosette and lack a discernable stalk
Stalk or stalking may refer to:
Behaviour
* Stalk, the stealthy approach (phase) of a predator towards its prey
* Stalking, an act of intrusive behaviour or unwanted attention towards a person
* Deer stalking, the pursuit of deer for sport
Biol ...
. If the leaves are covered with glandular hairs, they are sticky. The leaf blades may be circular in cross-section, flat or the margins may be curved upward, have a line-shaped to broadly elliptic or lance-shaped outline, with a pointy tip or tapering, the base much narrowed, like a leaf stalk
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in som ...
. The leaf margins are entire. The leaves may have prominent or more or less obscured parallel veins, and the leaf surfaces may be hairless, or carry long soft or coarse hairs. The texture of the leaves may be cartilaginous, leathery or herbaceous. The flowers are at the end of one or several branching inflorescence stalks, that carry several bracts much smaller than the leaves, at least substending each of the branches. These inflorescence stalks may be roughly hairy to hairless, and round or angular in cross-section. The compounded inflorescences may be compact or loosely composed raceme
A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the sh ...
s, panicle
A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is ...
s or corymb
Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficia ...
s. Each head is on a very short or long pedicel, except in ''C. cymosum'', where it is absent.
Remarkably, each flower head contains just one, bisexual, mauve, pink or white disc floret. The florets are enveloped by two whorls of involucral bracts
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, ...
. The outer whorl consists of two or three short bracts at the base. The inner whorl consist of only two, much larger, hairless or coarsely hairy bracts that usually are green in colour with purple tips or entirely tinged purple. The inner bracts form a sheath around the tube of the floret. The outer of these two bracts clasps the inner one, is keeled, split in two or three at the very tip, has three parallel veins along its length. The florets have a 5-merous Merosity (from the greek "méros," which means "having parts") refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a w ...
star-symmetrical trumpet-shaped corolla
Corolla may refer to:
*Corolla (botany), the petals of a flower, considered as a unit
*Toyota Corolla, an automobile model name
* Corolla (headgear), an ancient headdress in the form of a circlet or crown
* ''Corolla'' (gastropod), a genus of moll ...
consisting of a short tube near the base and five longer, spreading, oblong to line-shaped lobes at the top, and all contain both male and female parts. In the center of the corolla are five stamens with free filaments and line-shaped anthers fused into a tube, through which the style
Style is a manner of doing or presenting things and may refer to:
* Architectural style, the features that make a building or structure historically identifiable
* Design, the process of creating something
* Fashion, a prevailing mode of clothing ...
grows when the floret opens. The anthers have a shortly arrow-shaped base and no appendages at the top. The style sticks beyond the corolla, is round in cross-section, and splits in two style branches, which are coarsely hairy on outer surface. The dry, indehiscent
Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that o ...
, one-seeded fruits called cypselae, are line-shaped to elliptic, flattened in cross-section, and covered in long soft or coarse hairs. On the top of the cypselae is a whorl of crown-like or free pappus bristles.
''C. congestum'' has eight homologous sets of chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...
s (2n=16).
Species
The taxa within the genus ''Corymbium'' mainly differ in the width, indumentum
In biology, an indumentum (Latin, literally: "garment") is a covering of trichomes (fine "hairs") on a plantDavis, Peter Hadland and Heywood, Vernon Hilton (1963) ''Principles of angiosperm taxonomy'' Van Nostrandpage, Princeton, New Jersey, page ...
, prominence of the veins of the leaves, the hairiness of the conflorescence stalk, the stalk of the individual flower head (pedicel), the hairiness of the involucral bracts, the shape of the tip of these bracts, and the colour of the florets. The species, subspecies and varieties that are currently recognised, and their distinguishing features are summarized in the following table. Features of subtaxa identical to the typical subtaxon are not repeated.
File:Corymbium scabridum Rebelo 3.jpg, ''Corymbium africanum
''Corymbium'' is a genus of flowering plants in the daisy family comprising nine species. It is the only genus in the subfamily Corymbioideae and the tribe Corymbieae. The species have leaves with parallel veins, strongly reminiscent of monocots ...
'' subsp. ''scabridum'', habit
File:Corymbium scabridum Rebelo 2.jpg, ''C. africanum'' subsp. ''scabridum'', showing roughly hairy inflorescence stalk and involucre
File:Corymbium cymosum Rebelo 1.jpg, ''Corymbium cymosum
''Corymbium'' is a genus of flowering plants in the daisy family comprising nine species. It is the only genus in the subfamily Corymbioideae and the tribe Corymbieae. The species have leaves with parallel veins, strongly reminiscent of monocot ...
'', habit
File:Corymbium cymosum Rebelo 2.jpg, ''C. cymosum'' individual heads lack a stalk
File:Corymbium laxum Rebelo 1.jpg, ''Corymbium laxum
''Corymbium'' is a genus of flowering plants in the daisy family comprising nine species. It is the only genus in the subfamily Corymbioideae and the tribe Corymbieae. The species have leaves with parallel veins, strongly reminiscent of monocot ...
'', habit
File:Corymbium laxum Rebelo 2.jpg, ''C. laxum'' heads have a very long stalk
File:Corymbium congestum Rebelo 2.jpg, ''Corymbium congestum
''Corymbium'' is a genus of flowering plants in the daisy family comprising nine species. It is the only genus in the subfamily Corymbioideae and the tribe Corymbieae. The species have leaves with parallel veins, strongly reminiscent of monocots ...
'', habit
File:Corymbium congestum Rebelo 1.jpg, ''C. congestum'' with rough and glandular hairs on inflorescence stalk and involucre
File:Corymbium glabrum Vynbos 1.jpg, '' Corymbium glabrum'', habit
File:Corymbium glabrum vBerkel 2.jpg, ''C. glabrum'' with glabrous inflorescence stalk and involucre
File:Corymbium villosum vBerkel 1.jpg, '' Corymbium villosum'', habit
File:Corymbium villosum Helme 1.jpg, ''C. villosum'', corymb
Taxonomy
In 1680, Polish merchant, artist and naturalist Jacobus Breynius was the first to mention a species of plampers, describing it as ''Bupleuro affinis planta umbellifera folius liratis, longissimis are's-ear related to an umbelliferous plant with the longest lire-shaped leaves' (currently ''C. glabrum''). In 1696, the early English botanist Leonard Plukenet
Leonard Plukenet (1641–1706) was an English botanist, Royal Professor of Botany and gardener to Queen Mary.
Biography
Plukenet published ''Phytographia'' (London, 1691–1696) in four parts in which he described and illustrated rare exotic p ...
illustrated both ''C. glabrum'' and ''C. africanum'' in his book ''Almagestum Botanicum''. Plukenet described ''africanum'' as having ''cauliculo scabro ough branchlets
Ough may refer to:
* Ough (orthography), a letter sequence in English orthography
* Ough (surname)
* Ough, Nebraska
Ough is a former unincorporated community in Dundy County, Nebraska, United States. All that is left at Ough today is a farmhou ...
'. The name ''Corymbium'' was first proposed by Jan Frederik Gronovius
Jan Frederik Gronovius (also seen as Johann Frederik and Johannes Fredericus) (10 February 1690 in Leiden – 10 July 1762 in Leiden) was a Dutch botanist notable as a patron of Linnaeus.
John Clayton, a plant collector in Virginia sent him many ...
in 1737. In the Hortus Cliffortianus
The ''Hortus Cliffortianus'' is a work of early botanical literature published in 1737.
The work was a collaboration between Carl Linnaeus and the illustrator Georg Dionysius Ehret, financed by George Clifford in 1735-1736. Clifford, a wealthy A ...
published in 1737, Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...
distinguished the typical ''Corymbium'' and a variety ''α''. All of these names are invalid since they were publish before 1753, the start of the modern scientific naming.
In his ''Species Plantarum
' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...
'' (1753), Linnaeus recognised only ''Corymbium africanum''. French botanist of Scottish descent, Michel Adanson
Michel Adanson (7 April 17273 August 1806) was an 18th-century French botanist and naturalist who traveled to Senegal to study flora and fauna. He proposed a "natural system" of taxonomy distinct from the binomial system forwarded by Linnaeus. ...
described the genus ''Cantarena'' in 1763. In September 1767, Peter Jonas Bergius described ''C. scabridum'' based on Linnaeus' description in the ''Species Plantarum''. In October 1767, Linnaeus distinguished two species, ''C. glabrum'' and ''C. scabrum'', abandoning the name ''C. africanum''. Thomas Archibald Sprague
Thomas Archibald Sprague (7 October 1877, Edinburgh – 22 October 1958, Cheltenham, Gloucestershire, England) was a Scottish botanist. In 1938 he married botanist Mary Letitia Green, and together they authored several supplements to the ''Ind ...
in 1940 concluded that ''C. africanum'' belongs to the same species and is an older name than ''C. scabridum''. Nicolaas Laurens Burman
Nicolaas Laurens Burman (27 December 1734 – 11 September 1793) was a Dutch botanist.
He was the son of Johannes Burman (1707–1780). He succeeded his father to the chair of botany at the Athenaeum Illustre of Amsterdam., and at the Hortus ...
in 1768 mentioned two species, ''C. gramineum'' (now ''C. africanum'' subsp. ''scabridum'' var. ''gramineum'') and ''C. africanum''. Carl Linnaeus the Younger
Carl Linnaeus the Younger, Carolus Linnaeus the Younger, Carl von Linné den yngre (Swedish; abbreviated Carl von Linné d. y.), or ''Linnaeus filius'' ( Latin for ''Linnaeus the son''; abbreviated L.fil. (outdated) or L.f. (modern) as a botani ...
distinguished two additional species, ''C. villosum'' and ''C. filiforme'' (now ''C. africanum'' subsp. ''scabridum'' var. ''gramineum'') in 1781. Two more species, ''C. hirtum'' (a synonym of ''C. villosum'') and ''C. nervosum'' (a synonym of ''C. glabrum''), have been described by Carl Thunberg
Carl Peter Thunberg, also known as Karl Peter von Thunberg, Carl Pehr Thunberg, or Carl Per Thunberg (11 November 1743 – 8 August 1828), was a Swedish naturalist and an "apostle" of Carl Linnaeus. After studying under Linnaeus at Uppsala U ...
in 1794, who also recognised ''C. glabrum'' separately. In 1836, Augustin Pyramus de Candolle
Augustin Pyramus (or Pyrame) de Candolle (, , ; 4 February 17789 September 1841) was a Swiss botanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium. Within a couple of years de Candolle ...
described for the first time ''C. congestum'', ''C. cymosum'' and ''C. luteum'' (now ''C. africanum'' subsp. ''scabridum'' var. ''gramineum''). Danish botanist Christian Friedrich Ecklon
Christian Friedrich Ecklon (17 December 1795 – 1 December 1868) was a Danish botanical collector and apothecary. Ecklon is especially known for being an avid collector and researcher of plants in South Africa.
Biography
Ecklon was from Åbenr� ...
mentions but does not describe the name ''C. hirsutum'' in 1836 (now ''C. villosum'') in De Candolle's publication. The Irish botanist William Henry Harvey
William Henry Harvey, FRS FLS (5 February 1811 – 15 May 1866) was an Irish botanist and phycologist who specialised in algae.
Biography
Harvey was born at Summerville near Limerick, Ireland, in 1811, the youngest of 11 children. His fathe ...
distinguished in 1865 seven species and three varieties, among which the newly introduced names ''C. latifolium'' (''C. glabrum'' subsp. ''glabrum''), ''C. nervosum'' var. ''subulifolium'', ''C. scabrum'' var. ''filiforme'' and var. ''luteum'' (both now ''C. africanum'' subsp. ''scabridum'' var. ''gramineum''). John Hutchinson added ''C. fourcadei'' (now ''C. africanum'' subsp. ''scabridum'' var. ''fourcadei'') in 1932, and Robert Harold Compton
Robert Harold Compton (6 August 1886 in Tewkesbury – 11 July 1979 in Cape Town) was a South African botanist. The Compton Herbarium at Kirstenbosch National Botanical Garden, which he founded in Cape Town in 1939, was named in his honour. ...
described ''C. laxum'' in 1936. Markötter in 1939, recognized 12 species and two varieties, three of which were new and are upheld today: ''C. enerve'', ''C. theileri'' and ''C. rogersii'' (now ''C. glabrum'' var. ''rodgersii''). Frans M. Weitz, in his 1989 ''Revision
Revision is the process of revising.
More specifically, it may refer to:
* Patch (computing), Update, a modification of software or a database
* Revision control, the management of changes to sets of computer files
* ''ReVisions'', a 2004 antholo ...
of the genus Corymbium (Asteraceae)'', recognizes nine species, two subspecies and six varieties, including the new taxa ''C. elsiae'' and ''C. laxum'' subsp. ''bolusii''.
The name ''Corymbium'' has been derived from the Ancient Greek κόρυμβος (kórumbos), meaning a cluster, which refers to the confloresence, which in some of the species looks like a corymb
Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficia ...
. The common name in Afrikaans
Afrikaans (, ) is a West Germanic language that evolved in the Dutch Cape Colony from the Dutch vernacular of Holland proper (i.e., the Hollandic dialect) used by Dutch, French, and German settlers and their enslaved people. Afrikaans g ...
, heuningbossie (honey bush), is a reference to the copious production of nectar of the flowers.
Taxonomic history
Linnaeus included ''Corymbium'' in a group he called ''Syngenesia Monogamia'' with ''Impatiens'', ''Jasione'', ''Lobelia'' and ''Viola'', because these share an unusual morphology of the fower heads and flowers. In the outlines of his natural system of 1743 however, he positioned it in ‘’Ordo XXI’’, which he would later rename to the Compositae. In 1818, Henri Cassini
Count Alexandre Henri Gabriel de Cassini (9 May 1781 – 23 April 1832) was a French botanist and naturalist, who specialised in the sunflower family (Asteraceae) (then known as family Compositae).
He was the youngest of five children of Jacqu ...
placed ''Corymbium'' in the Vernonieae
Vernonieae is a tribe of about 1300 species of plants in the aster family. They are mostly found in the tropics and warmer temperate areas, both in the Americas and the Old World. They are mostly herbaceous plants or shrubs, although there is ...
, which was accepted by later authors including Lessing Lessing is a German surname of Slavic origin, originally ''Lesnik'' meaning "woodman".
Lessing may refer to:
A German family of writers, artists, musicians and politicians who can be traced back to a Michil Lessigk mentioned in 1518 as being a lin ...
, De Candolle, Harvey, Bentham
Bentham may refer to:
* Bentham, Gloucestershire in Badgeworth
* Bentham, North Yorkshire
* Bentham (surname)
* Bentham (''One Piece''), a character in Eiichiro Oda's manga ''One Piece''
* Bentham Grammar School, in North Yorkshire
* Bentham Ho ...
, Hoffmann
Hoffmann is a German surname.
People A
* Albert Hoffmann (1846–1924), German horticulturist
* Alexander Hoffmann (born 1975), German politician
*Arthur Hoffmann (politician) (1857–1927), Swiss politician and member of the Swiss Federal Coun ...
, S.B. Jones, and Weitz. It occurred to Bentham however, that ''Corymbium'' has a distinct, particularly long, cylindrical ovary that is densely set with rough hairs, and also has very short style branches. In members of the tribe Vernonieae however, style branches are long and slender, and the ovary is not densely hirsute. Chemical analysis showed that ''Corymbium'' contains so-called macrolide diterpenes, but lacks on the other hand sesquiterpene lactone
Sesquiterpene lactones (SLs) are a class of sesquiterpenoids that contain a lactone ring. They are most often found in plants of the family Asteraceae (daisies, asters). Other plant families with SLs are Umbelliferae (celery, parsley, carrots ...
s, which are characteristic for the Vernonieae. This has cast further doubt about the correct placement of Corymbium.
Phylogeny
Based on recent genetic analysis, it is now generally accepted that the subfamily Corymbioideae is sister to the Asteroideae
Asteroideae is a subfamily of the plant family Asteraceae. It contains about 70% of the species of the family. It consists of several tribes, including Astereae, Calenduleae, Eupatorieae, Gnaphalieae, Heliantheae, Senecioneae and Tageteae. Aster ...
. These two subfamilies, and the Cichorioideae share a deletion of nine base-pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...
s in the ndhF gene which is not present in any other Asteraceae. Current insights in the relationships of ''Corymbium'' to the closest Asterid subfamilies is represented by the following tree.
Distribution
The nine species of plampers are all endemic
Endemism is the state of a species being found 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 found els ...
to the Western Cape
The Western Cape is a province of South Africa, situated on the south-western coast of the country. It is the fourth largest of the nine provinces with an area of , and the third most populous, with an estimated 7 million inhabitants in 2020 ...
and Eastern Cape provinces of South Africa, in particular the Cape Fold Belt
The Cape Fold Belt is a fold and thrust belt of late Paleozoic age, which affected the sequence of sedimentary rock layers of the Cape Supergroup in the southwestern corner of South Africa. It was originally continuous with the Ventana Moun ...
and the foreland along the southern coast. They reach the Cedarberg
The Cederberg mountains are located near Clanwilliam, approximately 300 km north of Cape Town, South Africa at about . The mountain range is named after the endangered Clanwilliam cedar (''Widdringtonia wallichii''), which is a tree end ...
in the north, the Cape Peninsula
The Cape Peninsula ( af, Kaapse Skiereiland) is a generally mountainous peninsula that juts out into the Atlantic Ocean at the south-western extremity of the African continent. At the southern end of the peninsula are Cape Point and the Cape o ...
in the west, and as far as Grahamstown
Makhanda, also known as Grahamstown, is a town of about 140,000 people in the Eastern Cape province of South Africa. It is situated about northeast of Port Elizabeth and southwest of East London. Makhanda is the largest town in the Makana Loc ...
in the east, but do not occur in the Knysna forest. It usually grows on nutrient poor, shallow, quartzite sandy soils in the mountains and on heavy soils from slates, phyllites and granite of the Bokkeveld and Malmesbury Groups. One species grows on shallow calcareous soil on the limestone hills near Bredasdorp
Bredasdorp is a town in the Southern Overberg region of the Western Cape, South Africa, and the main economic and service hub of that region. It lies on the northern edge of the Agulhas Plain, about south-east of Cape Town and north of Cape A ...
and around De Hoop. On the Cape Peninsula, ''Corymbium'' species avoid the deep calcareous soils. The species occur from sea level to about .
Ecology
The species of plampers always grow in open communities with very little cover or at the edge of areas with more cover. They mostly flower during the summer, often about half a year after an overhead fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products.
At a certain point in the combustion reaction, called the ignition ...
and for two or three following summers. Later the plants remain predominantly in a vegetative state. Disturbance, such as clearing, may also trigger flowering. The flowers produce copious quantities of nectar, and bees, beetles, wasps and ants, can be seen visiting the flowers, and may be the principal pollinators.
Conservation
Of the seventeen taxa
In biology, a taxon ( back-formation from '' taxonomy''; plural 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 n ...
assigned to the 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 n ...
''Corymbium'', the risk of extinction for three varieties of ''C. africanum'' subsp. ''scabridum'' (i.e. var. ''scabridum'', var. ''fourcadei'', and var. ''gramineum''), has not been assessed. The continued survival of eight taxa is regarded to be of least concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...
: ''Corymbium africanum'' subsp. ''africanum'', ''C. congestum'', ''C. cymosum'', ''C. enerve'', ''C. glabrum'' var. ''glabrum'', ''C. glabrum'' var. ''rodgersii'', ''C. laxum'' subsp. ''laxum'', and ''C. villosum''. Two taxa are considered rare: ''C. laxum'' subsp. ''bolusii'' and ''C. elsiae''. Finally, ''C. theilerii'' has been assessed to be critically endangered.
References
{{Taxonbar, from1=Q851123, from2=Q15838762, from3=Q15838764
Asteraceae
Asteraceae genera
Endemic flora of South Africa