View source for Biology:Symphyotrichum

{{Short description|Genus of flowering plants in the family Asteraceae}}
{{Automatic taxobox
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| align        = center
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| caption      = '''''Symphyotrichum''''' species left–right, top–bottom: ''[[Biology:Symphyotrichum carnerosanum|S. carnerosanum]]'', ''[[Biology:Symphyotrichum chilense|S. chilense]]'', ''[[Biology:Symphyotrichum adnatum|S. adnatum]]'', ''[[Biology:Symphyotrichum concolor|S. concolor]]'', ''[[Biology:Symphyotrichum ericoides|S. ericoides]]'', ''[[Biology:Symphyotrichum defoliatum|S. defoliatum]]''.
| content={{Photomontage
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| photo1a = Symphyotrichum carnerosanum 137208712.jpg{{!}}''Symphyotrichum carnerosanum''
| photo1b = H20130729-9066—Symphyotrichum chilense—UCBG (14542414478).jpg{{!}}''Symphyotrichum chilense''
| photo2a = Symphyotrichum adnatum 57674395.jpg{{!}}''Symphyotrichum adnatum''
| photo2b = Symphyotrichum concolor 56416300.jpg{{!}}''Symphyotrichum concolor''
| photo3b = Symphyotrichum ericoides - Flickr - aspidoscelis (1).jpg{{!}}''Symphyotrichum ericoides''
| photo4a = Symphyotrichum defoliatum 5242734.jpg{{!}}''Symphyotrichum defoliatum''
|}}
|}}
| display_parents   = 3
| taxon             = Symphyotrichum
| authority         = [[Biography:Christian Gottfried Daniel Nees von Esenbeck|Nees]]
| type_species      = ''Symphyotrichum unctuosum''
| type_species_authority = Nees
| subdivision_ranks = Species
| subdivision       = See [[Biology:List of Symphyotrichum species|List of ''Symphyotrichum'' species]].
| synonyms_ref      = {{sfn|POWO|2021a}}
| synonyms          = 
{{Collapsible list
| {{Species list
| Aglotoma | [[Biography:Constantine Samuel Rafinesque|Raf.]]
| Anactis | Raf.
| Bindera | Raf.
| Brachyactis | Ledeb.
| Conyzanthus | Tamamsch.
| Diplactis | Raf.
| Fimbristima | Raf.
| Lasallea | Greene
| Leiachenis | Raf.
| Mesoligus | Raf.
| Myctanthes | Raf.
| Thinobia | Phil.
| Venatris | Raf.
| Virgaria | Raf. ex [[Biography:Augustin Pyramus de Candolle|DC.]]
| Virgulaster | Semple
| Virgulus | Raf.
| Xalkitis | Raf.
| }}
}}
}}

'''''Symphyotrichum''''' ({{IPAc-en|,|s|I|m|f|aI|@|'|t|r|I|k|@m}}) is a [[Biology:Genus|genus]] of over 100 species and naturally occurring hybrids of herbaceous [[Biology:Annual plant|annual]] and [[Biology:Perennial|perennial]] plants in the composite family, [[Biology:Asteraceae|Asteraceae]], most which were formerly treated within the genus ''[[Biology:Aster (genus)|Aster]]''. The majority are endemic to [[Earth:North America|North America]], but several also occur in the [[Place:West Indies|West Indies]], Central and [[Earth:South America|South America]], as well as one species in eastern [[Earth:Eurasia|Eurasia]]. Several species have been introduced to Europe as garden specimens, most notably New England aster (''[[Biology:Symphyotrichum novae-angliae|Symphyotrichum novae-angliae]]'') and New York aster (''[[Biology:Symphyotrichum novi-belgii|Symphyotrichum novi-belgii]]'').{{sfn|Brouillet|Semple|Allen|Chambers|2006}}{{sfn|Everitt|Lonard|Little|2007}}

==Description==

Brouillet, et al. wrote:
<blockquote>
Taxonomy of ''Symphyotrichum'' is difficult. Species are usually heterophyllous, some strongly so. Individuals in the spring, with basal rosettes, often have leaf shapes quite different from those with cauline leaves seen later in the season. [[Biology:Phyllary|Phyllary]] shape on first- and later-formed heads may differ. Individuals may vary considerably in plant size and array development depending upon growing conditions. The genetic diversity within each species also appears considerable.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}
</blockquote>

For all species in the genus, the ray florets are white, pink, blue, or purple. Disc florets are yellow to white, becoming pinkish, reddish purple, or brown when mature. There are 5 lobes on the disc florets of all species in the genus.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}

==Taxonomy==
German botanist [[Biography:Christian Gottfried Daniel Nees von Esenbeck|Christian Gottfried Daniel Nees von Esenbeck]] established this genus in 1833 because he thought that a plant he examined, now believed to be a cultivated variety of New York aster (''[[Biology:Symphyotrichum novi-belgii|Symphyotrichum novi-belgii]]''), which he called ''Symphyotrichum unctuosum'', was sufficiently distinct from the rest of the genus ''[[Biology:Aster (genus)|Aster]]'' to warrant its own genus. Nees emphasized the uniqueness of this plant in having its pappus hairs arranged in a coherent, basal ring.{{sfn|Nees|1833}} This structure is the basis for the scientific name of this genus, which derives from [[Social:Ancient Greek|Ancient Greek]] {{lang|grc|σύμφυσις}} (''sýmphysis'') "growing together" and {{lang|grc|θρίξ}} (''thríks''; [[Social:Word stem|stem]] {{lang|grc|τριχ-}} ''trich-'') "hair". However, this characteristic ring is not generally shared by most New York aster pappi, nor is it characteristic of any other plants included in the modern concept of ''Symphyotrichum''. Regardless, according to the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN), the timing of the genus' establishment gives it precedence over other names. The genus was resurrected in 1994 by American botanist Guy L. Nesom to group together species formerly included in the genus ''Aster'' in order to make modern genera [[Biology:Monophyletic|monophyletic]].{{sfn|Nesom|1994}}

===Subdivisions===
''Symphyotrichum'' has been divided into five subgenera:

====Subgenus ''Ascendentes''====
This subgenus includes two species from the western United States and Canada that originated as hybrids between species in the subgenera ''Symphyotrichum'' and ''Virgulus''.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}{{sfn|Semple|n.d.a}}

====Subgenus ''Astropolium''====
This subgenus includes about 10 species found across the Americas in [[Earth:Salt marsh|salt marsh]]es and [[Earth:Salt pan (geology)|salt flats]].{{sfn|Brouillet|Semple|Allen|Chambers|2006}}{{sfn|Semple|n.d.b}}

====Subgenus ''Chapmaniana''====
This subgenus includes a single species, ''[[Biology:Symphyotrichum chapmanii|S. chapmanii]]'', found in Alabama and Florida.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}

====Subgenus ''Symphyotrichum''====
This subgenus includes about 65 species occurring across North America, including a few species in Central America and the Caribbean, with one species also occurring in Eurasia.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}

====Subgenus ''Virgulus''====
This subgenus includes about 28 species occurring across North America, including a few species in Central America and the Caribbean.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}

==Distribution==
As a whole, ''Symphyotrichum'' is native throughout the Americas, with one species, ''[[Biology:Symphyotrichum ciliatum|S. ciliatum]]'', also native to eastern [[Earth:Eurasia|Eurasia]]. Several species have been introduced to Europe and other parts of the world.{{sfn|Brouillet|Semple|Allen|Chambers|2006}} Most species are native to Mexico, the United States, and Canada, with several species occurring in the [[Place:West Indies|West Indies]] and Central America.{{sfn|Brouillet|Semple|Allen|Chambers|2006}}{{sfn|Gann|2021}}{{sfn|Britton|1914}}{{sfn|POWO|2021b}} Most members of subgenus ''Astropolium'' are restricted to South America.{{sfn|Semple|n.d.b}}{{sfn|Hind|Strange|2019}}

==Species==
{{As of|2021|June}}, [[Biology:Catalogue of Life|Catalogue of Life]] listed 106 accepted species and identified naturally-occurring hybrids, including the following:{{sfn|Hassler|2021}}
* ''[[Biology:Symphyotrichum ascendens|Symphyotrichum ascendens]]'' <small>(Lindl.) G.L.Nesom</small> &ndash; western aster, longleaf aster, intermountain aster
* ''[[Biology:Symphyotrichum campestre|Symphyotrichum campestre]]'' <small>(Nutt.) G.L.Nesom</small> &ndash; western meadow aster
* ''[[Biology:Symphyotrichum chilense|Symphyotrichum chilense]]'' <small>(Nees) G.L.Nesom</small> &ndash; Pacific aster, common California aster
* ''[[Biology:Symphyotrichum cordifolium|Symphyotrichum cordifolium]]'' <small>(L.) G.L.Nesom</small> &ndash; heartleaf aster, common blue wood aster
* ''[[Biology:Symphyotrichum defoliatum|Symphyotrichum defoliatum]]'' <small>(Parish) G.L.Nesom</small> &ndash; San Bernardino aster
* ''[[Biology:Symphyotrichum depauperatum|Symphyotrichum depauperatum]]'' <small>(Fernald) G.L.Nesom</small> &ndash; serpentine aster
* ''[[Biology:Symphyotrichum dumosum|Symphyotrichum dumosum]]'' <small>(L.) G.L.Nesom</small> &ndash; bushy aster, rice-button aster, 
* ''[[Biology:Symphyotrichum eatonii|Symphyotrichum eatonii]]'' <small>(A.Gray) G.L.Nesom</small> &ndash; Eaton's aster
* ''[[Biology:Symphyotrichum ericoides|Symphyotrichum ericoides]]'' <small>(L.) G.L.Nesom</small> &ndash; white aster, heath aster
* ''[[Biology:Symphyotrichum falcatum|Symphyotrichum falcatum]]'' <small>(Lindl.) G.L.Nesom</small> &ndash; white prairie aster, falcate aster, western heath aster
* ''[[Biology:Symphyotrichum frondosum|Symphyotrichum frondosum]]'' <small>(Nutt.) G.L.Nesom</small> &ndash; short-rayed alkali aster
* ''[[Biology:Symphyotrichum georgianum|Symphyotrichum georgianum]]'' <small>(Alexander) G.L.Nesom</small> &ndash; Georgia aster
* ''[[Biology:Symphyotrichum greatae|Symphyotrichum greatae]]'' <small>(Parish) G.L.Nesom</small> &ndash; Greata's aster
* ''[[Biology:Symphyotrichum hallii|Symphyotrichum hallii]]'' <small>(A.Gray) G.L.Nesom</small> &ndash; Hall's aster 
* ''[[Biology:Symphyotrichum laeve|Symphyotrichum laeve]]'' <small>(L.) Á.Löve & D.Löve</small> &ndash; smooth aster, smooth leaved aster, glaucous aster
* ''[[Biology:Symphyotrichum lanceolatum|Symphyotrichum lanceolatum]]'' <small>(Willd.) G.L.Nesom</small> &ndash; panicled aster, tall white aster
* ''[[Biology:Symphyotrichum lateriflorum|Symphyotrichum lateriflorum]]'' <small>(L.) Á.Löve & D.Löve</small> &ndash; calico aster
* ''[[Biology:Symphyotrichum lentum|Symphyotrichum lentum]]'' <small>(Greene) G.L.Nesom</small> &ndash; Suisun Marsh aster
* ''[[Biology:Symphyotrichum novae-angliae|Symphyotrichum novae-angliae]]'' <small>(L.) G.L.Nesom</small> &ndash; New England aster
* ''[[Biology:Symphyotrichum novi-belgii|Symphyotrichum novi-belgii]]'' <small>(L.) G.L.Nesom</small> &ndash; New York aster
* ''[[Biology:Symphyotrichum oblongifolium|Symphyotrichum oblongifolium]]'' <small>(Nutt.) G.L.Nesom</small> &ndash; aromatic aster
* ''[[Biology:Symphyotrichum oolentangiense|Symphyotrichum oolentangiense]]'' <small>(Riddell) G.L.Nesom</small> &ndash; sky-blue aster, azure aster
* ''[[Biology:Symphyotrichum pilosum|Symphyotrichum pilosum]]'' <small>(Willd.) G.L.Nesom</small> &ndash; hairy aster, frost aster
* ''[[Biology:Symphyotrichum prenanthoides|Symphyotrichum prenanthoides]]'' <small>(Muhl. ex Willd.) G.L.Nesom</small> &ndash; crooked-stem aster
* ''[[Biology:Symphyotrichum puniceum|Symphyotrichum puniceum]]'' <small>(L.) Á.Löve & D.Löve</small> &ndash; purplestem aster, red-stemmed aster, swamp aster
* ''[[Biology:Symphyotrichum sericeum|Symphyotrichum sericeum]]'' <small>(Vent.) G.L.Nesom</small> &ndash; western silver aster, silky aster
* ''[[Biology:Symphyotrichum shortii|Symphyotrichum shortii]]'' <small>(Lindl.) G.L.Nesom</small> &ndash; Short's aster
* ''[[Biology:Symphyotrichum subulatum|Symphyotrichum subulatum]]'' <small>(Michx.) G.L.Nesom</small> &ndash; eastern annual saltmarsh aster

== Reproduction ==
{{Multiple image
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<!--image 1-->
| image1            = Asteraceae flower parts ray floret.svg
| alt1              = refer to caption and text
| caption1          = {{Center|Diagram of ray floret}}
{{Ordered list
| list_style_type = decimal
| corolla
| style
| stigma
| calyx
| ovary
}}
<!--image 2-->
| image2            = Asteraceae flower parts disk floret.svg
| alt2              = refer to caption and text
| caption2          = {{Center|Diagram of disk floret}}
{{Ordered list
| list_style_type = decimal
| stigma
| style
| anthers
| corolla
| calyx
| ovary
}}
}}
Ray florets in the ''Symphyotrichum'' genus are exclusively female, each having a pistil (with [[Biology:Style (botany)|style]], [[Biology:Stigma (botany)|stigma]], and [[Biology:Ovary (botany)|ovary]]) but no [[Biology:Stamen|stamen]]. Ray florets accept [[Biology:Pollen|pollen]] and each can develop a [[Biology:Seed|seed]], but they produce no pollen.{{Sfn|Brouillet|Semple|Allen|Chambers|2006}}

Each ray floret has a strap-shaped corolla (or ligule) formed from three vestigial [[Biology:Petal|petal]]s which are fused together. The floret contains one inferior ovary, and this ovary contains one [[Biology:Ovule|ovule]].{{efn|group=n|Asteraceae ovaries are called ''inferior'' because the floral parts attach above the ovary. See also [[Biology:Asteraceae#Floral structures|Asteraceae § Floral structures]] and [[Biology:Gynoecium|Gynoecium]].}} The ovary has an attached style that extends outward from between the ray floret corolla and the rest of the flower head. As the ray floret is blooming, the stigma at the top of the style splits into two lobes.{{Sfn|Morhardt|Morhardt|2004|pp=30–31}}

Disk florets in the ''Symphyotrichum'' genus are androgynous, each with both male (stamen, anthers, and filaments) and female reproductive parts; thus, a disk floret produces pollen and can develop a seed. The disk floret has five petals, sometimes referred to as ''lobes'', which are fused into its own corolla in the shape of a tube.{{Sfn|Brouillet|Semple|Allen|Chambers|2006}}

The male stamen is inside the tube-shaped corolla of the disk floret. It has five anthers, five filaments, and produces pollen. The anthers and filaments are readily visible as separate entities in non-Asteraceae species. Here, they are fused together to form a cylinder, or tube, with their pollen on the inside only. This male anther cylinder surrounds the female style and stigma. As the style is maturing, it elongates up through the anther cylinder, gathering the pollen on its stigma along the way.{{Sfn|Morhardt|Morhardt|2004|p=30}}

The ovary is at the bottom of the disk floret style. As with the ray floret, the disk floret stigma has two lobes that are fused together. The disk floret's stigma stays closed while pollen is on it, keeping its ovary safe from self-pollination. After the pollen has been collected and carried off by one or more pollinators, the stigma begins to split into two lobes, opening the style so that the disk floret ovary becomes accessible to receive pollen from another plant.{{Sfn|Morhardt|Morhardt|2004|p=30}}

== Notes ==
{{Notelist|group=n}}

== Citations == 
{{Reflist|20em}}

== References ==
{{Refbegin|30em}}
*{{Cite journal 
| date        = January 1914
| title       = Studies of West Indian Plants-V
| url         = https://www.jstor.org/stable/2479432  <!-- please do not add ending slash; that will break JSTOR links -->
| journal     = Bulletin of the Torrey Botanical Club
| volume      = 41
| issue       = 1
| pages       = 1–24
| doi         = 10.2307/2479432
| doi-access  = 
| jstor       = 2479432
| language    = en
| access-date = 27 January 2021
| via         = [[Organization:JSTOR|JSTOR]]
| url-access= subscription
}}
*{{Cite eFloras <!-- Citation bot bypass -->
| 1
| 132022
| Symphyotrichum 
| volume       = 20
| date         = 2006
| access-date  = 4 November 2020
}}
*{{Cite book 
| last1     = Everitt | first1 = J.H. 
| last2     = Lonard  | first2 = R.L. 
| last3     = Little  | first3 = C.R. 
| year      = 2007 
| title     = Weeds in South Texas and Northern Mexico 
| publisher = Texas Tech University Press 
| location  = Lubbock 
| isbn      = 978-0-89672-614-7
| language  = en
}}
*{{Cite web
| last1        = Gann | first1 = G.D. <!--George D. Gann-->
| year         = 2021
| title        = ''Symphyotrichum lucayanum'' (Britton) G.L. Nesom - Pineland aster 
| url          = https://regionalconservation.org/ircs/database/plants/PlantPageBAH.asp?TXCODE=Sympluca 
| website      = Floristic Inventory of the Bahama Archipelago Database Online (BETA)
| publisher    = The Institute for Regional Conservation
| location     = Delray Beach, Florida
| archive-url  = https://web.archive.org/web/20210127021426/https://regionalconservation.org/ircs/database/plants/PlantPageBAH.asp?TXCODE=Sympluca
| archive-date = 27 January 2021
| url-status   = live
| language     = en
| access-date  = 27 January 2021
}}
*{{Cite book <!-- Citation bot bypass --> 
| last1         = Hassler | first1 = M. <!-- Michael Hassler -->
| date          = 17 March 2021
| chapter       = ''Symphyotrichum'' Nees – World Plants: Synonymic Checklists of the Vascular Plants of the World
| chapter-url   = https://www.catalogueoflife.org/data/search?TAXON_ID=7QW7&facet=rank&facet=issue&facet=status&facet=nomStatus&facet=nameType&facet=field&limit=50&offset=0&rank=species&reverse=false&status=accepted
| editor1-last  = Roskov         | editor1-first  = Y.
| editor2-last  = Ower           | editor2-first  = G.
| editor3-last  = Orrell         | editor3-first  = T.
| editor4-last  = Nicolson       | editor4-first  = D.
| editor5-last  = Bailly         | editor5-first  = N.
| editor6-last  = Kirk           | editor6-first  = P.M.
| editor7-last  = Bourgoin       | editor7-first  = T.
| editor8-last  = DeWalt         | editor8-first  = R.E.
| editor9-last  = Decock         | editor9-first  = W.
| editor10-last = van Nieukerken | editor10-first = E.J.
| editor11-last = Penev          | editor11-first = L.
| title         = Species 2000 {{&}} ITIS Catalogue of Life, 10 June 2021
| location      = Leiden, Netherlands
| publisher     = Naturalis Biodiversity Center
| issn          = 2405-8858
| language      = en
| access-date   = 31 July 2021
}}
*{{Cite journal 
| last1    = Hind    | first1 = N. <!-- Nicholas Hind -->
| last2    = Strange | first2 = K. <!-- Kit Strange -->
| date     = 4 January 2019 
| title    = ''Symphyotrichum vahlii''
| url      = https://onlinelibrary.wiley.com/doi/abs/10.1111/curt.12259
| url-access = subscription
| journal  = Curtis's Botanical Magazine
| volume   = 35 
| issue    = 4 
| pages    = 380–395 
| doi      = 10.1111/curt.12259
| s2cid    = 91385545
| language = en
}}
*{{Cite book
| last1        = Morhardt | first1 = S.
| last2        = Morhardt | first2 = E.
| date         = 2004
| title        = California Desert Flowers: An Introduction to Families, Genera, and Species
| publisher    = University of California Press
| location     = Berkeley
| isbn         = 0-520-24003-0
| language     = en
}}
*{{Cite book
| ref         = {{Sfnref|Nees|1833}}
| year        = 1833 
| title       = Genera et species asterearum 
| trans-title = Genera and Species of the Astereae
| url         = https://biodiversitylibrary.org/page/32622944/
| publisher   = Leonardi Schrag 
| location    = Nuremberg 
| page        = 135
| doi         = 10.5962/bhl.title.46989 
| doi-access  = free
| language    = Latin 
| via         = [[Social:Biodiversity Heritage Library|Biodiversity Heritage Library]] 
}}
*{{Cite journal
| publication-date = 31 January 1995
| date         = September 1994
| title        = Review of the taxonomy of ''Aster'' sensu lato (Asteraceae: Astereae), emphasizing the New World species
| journal      = Phytologia
| volume       = 77
| issue        = 3
| pages        = 141–297
| issn         = 0031-9430
| url          = https://www.biodiversitylibrary.org/page/12959940/
| publisher    = Michael J. Warnock
| location     = Huntsville, Texas
| language     = en
| access-date  = 24 December 2020 
| via          = [[Social:Biodiversity Heritage Library|Biodiversity Heritage Library]] 
}}
*{{Cite POWO <!-- Citation bot bypass-->
| last        = POWO
| id          = 30073935-2
| date        = 2021a
| title       = ''Symphyotrichum'' Nees
| access-date = 31 July 2021
}}
*{{Cite POWO <!-- Citation bot bypass-->
| last         = POWO
| id           = 981855-1
| date         = 2021b 
| title        = ''Symphyotrichum leonis'' (Britton) G.L.Nesom 
| access-date  = 5 January 2022
}}
*{{Cite web 
| date         = n.d.a
| title        = ''Symphyotrichum'' subg. ''Ascendentes''
| url          = https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/symphyotrichum-subg-ascendentes 
| website      = www.uwaterloo.ca
| location     = Ontario
| language     = en
| archive-url  = https://web.archive.org/web/20220214123540/https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/symphyotrichum-subg-ascendentes
| url-status   = live
| archive-date = 14 February 2022
| access-date  = 18 September 2022
}}
*{{Cite web 
| date         = n.d.b
| title        = ''Symphyotrichum'' subg. ''Astropolium''
| url          = https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/symphyotrichum-subg-astropolium 
| website      = www.uwaterloo.ca
| location     = Ontario
| language     = en
| archive-url  = https://web.archive.org/web/20220214123545/https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/symphyotrichum-subg-astropolium
| url-status   = live
| archive-date = 14 February 2022
| access-date  = 18 September 2022
}}

{{Refend}}

==External links==

{{Taxonbar|from=Q2629596}}

[[Category:Symphyotrichum| ]]
[[Category:Asteraceae genera]]

{{Sourceattribution|Symphyotrichum}}