Cotula

{{short description|Genus of flowering plants in the sunflower family}} {{For|the town|Cotula, Tennessee}} {{Automatic taxobox |image = BrassButtonsHand.jpg |image_caption = ''Cotula coronopifolia'' |display_parents = 2 |taxon = Cotula |authority = L. |type_species = ''Cotula coronopifolia'' |type_species_authority = L.<ref>lectotype designated by M. L. Green, Prop. Brit. Bot. 182 (1929)</ref><ref name=r/> |synonyms_ref = <ref name=b>[https://archive.today/20141115204421/http://dixon.iplantcollaborative.org/CompositaeWeb/default.aspx?Page=NameDetails&TabNum=0&NameId=b4a7881d-092c-40d6-848b-583c8614183a Flann, C (ed) 2009+ Global Compositae Checklist ]</ref> |synonyms = * ''Baldingeria'' Neck. * ''Gymnogyne'' Steetz * ''Peyrousea'' DC. * ''Lancisia'' Lam. * ''Pleiogyne'' K.Koch * ''Strongylosperma'' Less. * ''Cenia'' Comm. ex Juss. * ''Cenia'' sect. ''Actinocenia'' DC. * ''Hippia'' L.f. * ''Ctenosperma'' Hook.f. * ''Lancisia'' Fabr. * ''Machlis'' DC. * ''Otochlamys'' DC. * ''Cotyla'' O.Kuntze & T. von Post }}

'''''Cotula''''' is a genus of flowering plant in the sunflower family.<ref>[https://www.biodiversitylibrary.org/page/358912#page/333/mode/1up Linnaeus, Carl von. 1753. Species Plantarum 2: 891-892] in Latin</ref><ref name=r>[http://www.tropicos.org/Name/40015278 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, leaf division, involucre, receptacle and achenes. This makes it difficult to define them by comparing their morphology. 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. This genus was first mentioned by Carl Linnaeus, who described four species in his first edition (1753) of ''Species Plantarum''. In 1867 the genus was subdivided by George Bentham<ref>Bentham, G., 1867: "Flora Australiensis", Vol. 3. Reeve, London.</ref> 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 numbers : * section ''Cotula'' : largest section with about 40 species; mostly in South Africa, a few in North Africa 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 and Asia (often lumped as ''C. anthemoides''), Central and South America (''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 and the Falkland Islands (the type species ''C. scariosa''), New Zealand, the Subantarctic Islands (together 24) and five species from Australia and New Zealand.; 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 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<ref name=b/> {{columns-list|colwidth=22em| * ''Cotula abyssinica'' Sch.Bip. ex A.Rich. * ''Cotula alpina'' (Hook.f.) Hook.f. * ''Cotula andreae'' (E.Phillips) K.Bremer & Humphries * ''Cotula anthemoides'' L. * ''Cotula aurea'' L. * ''Cotula australis'' (Sieber ex Spreng.) Hook.f. * ''Cotula barbata'' DC. * ''Cotula bipinnata'' Thunb. * ''Cotula bracteolata'' E.Mey. ex DC. * ''Cotula burchellii'' DC. * ''Cotula ceniifolia'' DC. * ''Cotula chamaemelifolia'' Ehrenb. ex K.Koch * ''Cotula cinereum '' * ''Cotula coronopifolia'' L. * ''Cotula cotuloides'' (Steetz) Druce * ''Cotula cryptocephala'' Sch.Bip. ex A.Rich. * ''Cotula dielsii'' Muschl. * ''Cotula duckittiae'' (L.Bolus) K.Bremer & Humphries * ''Cotula eckloniana'' (DC.) Levyns * ''Cotula elongata'' B.Vogel * ''Cotula filifolia'' Thunb. * ''Cotula goughensis'' R.N.R.Br. * ''Cotula gymnogyne'' F.Muell. ex Benth. * ''Cotula hemisphaerica'' Wall. ex Benth. & Hook.f. * ''Cotula heterocarpa'' DC. * ''Cotula hispida'' (DC.) Harv. * ''Cotula laxa'' DC. * ''Cotula leptalea'' DC. * ''Cotula lineariloba'' (DC.) Hilliard * ''Cotula loganii'' Hutch. * ''Cotula macroglossa'' Bolus ex Schltr. * ''Cotula mariae'' K.Bremer & Humphries * ''Cotula melaleuca'' Bolus * ''Cotula membranifolia'' Hilliard * ''Cotula mexicana'' (DC.) Cabrera * ''Cotula microglossa'' (DC.) O.Hoffm. & Kuntze ex Kuntze * ''Cotula montana'' Compton * ''Cotula moseleyi'' Hemsl. * ''Cotula myriophylloides'' Harv. * ''Cotula nigellifolia'' (DC.) K.Bremer & Humphries * ''Cotula nudicaulis'' Thunb. * ''Cotula paludosa'' Hilliard * ''Cotula paradoxa'' Schinz * ''Cotula pedicellata'' Compton * ''Cotula pedunculata'' (Schltr.) E.Phillips * ''Cotula pterocarpa'' DC. * ''Cotula pusilla'' Thunb. * ''Cotula radiata'' O.Hoffm. ex Kuntze * ''Cotula radicalis'' (Killick & Claassen) Hilliard & B.L.Burtt * ''Cotula reptans'' (Benth.) Benth. * ''Cotula rosea'' Boj. ex Less. * ''Cotula sericea'' L.f. * ''Cotula socialis'' Hilliard * ''Cotula sororia'' DC. * ''Cotula squalida'' (Hook.f.) Hook.f. * ''Cotula tenella'' E.Mey. ex DC. * ''Cotula thunbergii'' Harv. * ''Cotula turbinata'' L. * ''Cotula villosa'' DC. * ''Cotula vulgaris'' Levyns * ''Cotula zeyheri'' Fenzl }}

==Uses== ''Cotula'' is used in New Zealand as ground cover for bowling greens, playing fields on which the ball-game of bowls is played.<ref name="Zealand1979">{{cite book|author=The Royal Society of New Zealand|title=New Zealand Journal of Crop and Horticultural Science/Experimental Agriculture|url=https://books.google.com/books?id=zsis5NtbG6wC&pg=PA257|accessdate=24 August 2012|date=September 1979|publisher=The Royal Society of New Zealand|pages=257–}}</ref><ref name="England)1999">{{cite book|author=Sports Turf Research Institute (Bingley, England)|title=International turfgrass bulletin|url=https://books.google.com/books?id=uXRYAAAAYAAJ|accessdate=24 August 2012|year=1999|publisher=Sports Turf Research Institute}}</ref>

==Footnotes== {{Reflist}}

==References== * {{Cite journal |author=David G. Lloyd |year=1972 |title=A revision of the New Zealand, Subantarctic, and South American species of ''Cotula'', section ''Leptinella'' |journal=New Zealand Journal of Botany |volume=10 |issue=2 |pages=277–372 |doi=10.1080/0028825X.1972.10429156 |doi-access=free |bibcode=1972NZJB...10..277L }}

==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.

==External links== * {{Wikispecies-inline|Cotula|''Cotula''}} * {{Commons category-inline|Cotula|''Cotula''}}

Category:Cotula Category:Asteraceae genera Category:Taxonomy articles created by Polbot Category:Botanical taxa named by Carl Linnaeus