flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
in the sunflower family.Tropicos, ''Cotula'' L. /ref> It includes plants known generally as water buttons or buttonweeds.
The species within this genus can vary extensively in their
habit
A habit (or wont as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously.
involucre
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, or o ...
, receptacle and achenes. This makes it difficult to define them by comparing their
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 ...
. The genus can only be defined by looking at the corollas of their flowers. Most are disciform (lacking ray florets). These corollas may be tubular, reduced or even absent. Another characteristic is their solitary heads growing on a peduncle.
Taxonomy
''Cotula'' is the largest genus found in the Southern Hemisphere of the tribe
Anthemideae
Anthemideae is a tribe of flowering plants in the family, Asteraceae, and the subfamily Asteroideae. They are distributed worldwide with concentrations in central Asia, the Mediterranean Basin, and southern Africa.Oberprieler, C., et al. (2007) ...
. This genus was first mentioned by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
, who described four species in his first edition (1753) of '' Species Plantarum''. In 1867 the genus was subdivided by
George Bentham
George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studie ...
Bentham, G., 1867: "Flora Australiensis", Vol. 3. Reeve, London. into three sections. Since his account, only a few changes have been made but the number of species has remained more or less stable. The sections possess different basic
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 are ...
numbers :
* section ''Cotula'' : largest section with about 40 species; mostly in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, a few in
North Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...
and Australia + the cosmopolitan species ''C. coronopifolia'' and the widespread species ''C. turbinata;'' this section also includes the former genera ''Cenia'' and ''Otochlamys''; basic chromosome numbers x = 8 and x = 10.
* section ''Strongylosperma'' (Less.) Benth.: a total of eight species, found in warmer parts of
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 ...
and
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 are ...
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
(''C. mexicana'') and Australia (five species, including ''C. australis''); basic chromosome number : x = 18
* section ''Leptinella'' (Cass.) Hook f. : the remaining thirty species, found in
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
and the
Falkland Islands
The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...
(the type species ''C. scariosa''),
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 count ...
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 count ...
.; the species in this section have a distinctive characteristic not found in the other sections : inflated pistillate corollas; basic chromosome number : x = 13. See also '' Leptinella''.
David G. Lloyd has proposed that the five species from Australia and
New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...
are distinctive enough from the other species from the section ''Leptinella'' to be brought under a new section with the proposed name ''Oligoleima'' (type species ''C. longipes'').
; Species
Uses
''Cotula'' is used in
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 count ...
as ground cover for bowling greens, playing fields on which the ball-game of bowls is played
Footnotes
References
*
Further reading
* Jakubowsky, G. and L. Mucina. (2007). Phylogeny of the South African centred plant genus ''Cotula'' (Asteraceae). ''South African Journal of Botany'' 73:2 292.