{{Taxobox
| color = lightgreen
| name = Asteraceae
| image = Aster-alpinus.JPG
| image_width = 250px
| image_caption = ''[[Aster alpinus]]''
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Magnoliopsida]]
| ordo = [[Asterales]]
| familia = '''Asteraceae'''
| familia_authority = [[Martynov]], 1820
| synonyms = ''Compositae'' <small>[[Giseke]]</small>
| type_genus = ''[[Aster (flower)|Aster]]''
| type_genus_authority= [[Carolus Linnaeus|L.]]
| diversity =
| diversity_link = List of Asteraceae genera
| subdivision_ranks =
| subdivision =
}}

The family '''Asteraceae''' or '''Compositae''', known as the '''aster''', '''daisy''' or '''sunflower family''', is the second largest family of [[flowering plant]]s, after [[Orchidaceae]], in terms of number of species.

The name 'Asteraceae' is derived from the type genus ''[[Aster (flower)|Aster]]'', while 'Compositae', an older but still valid <ref>[http://ibot.sav.sk/icbn/main.htm International Code of Botanical Nomenclature]</ref> name, means ''composite'' and refers to the peculiar [[inflorescence]].

According to the [[Royal Botanical Gardens]] of Kew the family comprises more than 1,600 genera and 23,000 species. The largest genera are ''[[Senecio]]'' (1,500 species), ''[[Vernonia]]'' (1,000 species), ''[[Cousinia]]'' (600 species), <!-- ''[[Eupatorium]]'' (600 species), [not anymore!] -->''[[Centaurea]]'' (600 species). The circumscription of the genera is often problematic and some of these have been frequently divided into minor subgroups <ref name="Judd">Judd & al., Plant Systematics: A Phylogenetic Approach</ref>.

Asteraceae are cosmopolitan, but most common in the temperate regions and tropical mountains.

==Taxonomy==
The family has been universally recognised and placed in the order [[Asterales]].

Traditionally two subfamilies were recognised: [[Asteroideae]] (or 'Tubuliflorae') and [[Cichorioideae]] (or 'Liguliflorae'). The latter is [[paraphyletic]] and has been divided into many minor groups in most newer systems. The article is based the subdivisions proposed by the [[APG system]].

A tentative [[cladogram]] is shown below. The diamond denotes a very poorly supported branching (<50%), the dot a poorly supported branching (<80%) <ref name="APW">Stevens, P.F., [http://www.mobot.org/MOBOT/research/APweb/orders/asteralesweb.htm'' Angiosperm Phylogeny Website'']</ref>.
{{clade|style=font-size:80%;line-height:75%
|1={{clade|1='''[[Barnadesioideae]]''': 9 genera, 93 species. [[South America]], mainly the [[Andes]].
|2={{clade|1='''[[Stifftia]]''' and close relatives: [[South Amrica]] and [[Asia]].|label2=♦
|2={{clade|1='''[[Mutisioideae]]''': 58 genera, 750 species. [[South America]].|label2=•
|2={{clade|1='''[[Gochnatioideae]]''': 4 or 5 genera, 90 species.|2={{clade
|1='''[[Hecastocleioideae]]''': Only ''[[Hecastocleis shockleyi]]''. South-western [[U.S.A.]].|2={{clade
|1='''[[Carduoideae]]''': 83 genera, 2,500 species. Worldwide.|2={{clade
|1='''[[Pertyoideae]]''': 5 or 6 genera, 70 species.
|2={{clade|1='''[[Gymnarrhenoideae]]''': Only ''[[Gymnarrhena micrantha]]''. Northern [[Africa]].|label2=•
|2={{clade|1='''[[Cichorioideae]]''': 224 genera, 3,200 species. Worldwide.|2={{clade
|1='''[[Corymbioideae]]''': Only the genus ''[[Corymbium]]'', with 7 species.|label2=•|2={{clade
|1='''[[Asteroideae]]''': 1,130 genera and 16,200 species. Worldwide.}}}}}}}}}}}}}}}}}}}}}}}}

It is noteworthy that the four subfamilies [[Asteroideae]], [[Cichorioideae]], [[Carduoideae]] and [[Mutisioideae]] comprise 99% of the specific diversity of the whole family (appr. 70%, 14%, 11% and 3% respectively).

== Description ==
Asteraceae are most usually [[herb]]s, but some [[tree]]s and [[Vine|climber]]s do exist. They are generally easy to distinguish, mainly because of their peculiar [[inflorescence]] and share many [[apomorphy|apomorphies]] <ref name="Judd"/>.

===Leaves and stems===
The [[leaf|leaves]] and the stems very often contain secretory canals with [[resin]] or [[latex]] (particularly common among the Cichorioideae). The leaves can be [[phyllotaxis|alternate]], [[phyllotaxis|opposite]], or [[phyllotaxis|whorled]]. They may be simple, but are often deeply [[leaf#morphology|lobed]] or otherwise [[leaf#morphology|incised]], often [[leaf#morphology|conduplicate]] or [[leaf#morphology|revolute]]. The margins can be entire or dentate.

===Flowers===
[[Image:Bidens_flwr.jpg|thumb|A typical Asteraceae flower head (here ''[[Bidens torta]]'') showing the individual flowers]]
The most evident characteristic of Asteraceae is perhaps their [[inflorescence]]: a specialised [[capitulum]], technically called a ''calathid'' or ''calathidium'', but generally referred to as ''flower head'' or, alternatively, simply ''capitulum'' <ref>Usher, 1966</ref>. The capitulum is a contracted [[raceme]] composed of numerous individual sessile [[flower]]s, called the ''florets'', that share the same [[receptacle]].

The capitulum of the Asteraceae has evolved many characteristics that make it look superficially like a big single flower. This kind of flower-like inflorescences are quite widespread amongst plants and have been given the name of ''[[pseudanthium|pseudanthia]]''.

Many [[bract]]s form an [[involucre]] under the basis of the capitulum and may simulate the [[sepal]]s of the pseudanthium. These are mostly herbaceous but can also be brightly coloured (e.g. ''[[Helichrysum]]'') or have a scarious texture. The bracts are mostly free and arranged in one to many rows, overlapping like the tiles of a roof (''imbricate'').

[[Image:Carduus flowerdiagram.png|thumb|left|Flower diagram of ''[[Carduus]]'' (Carduoideae)]]The florets primitively have five [[petal]]s and may be [[actinomorphic]] or [[zygomorphic]]. The ''disc florets'' are usually actinomorphic, their petals are fused so that the [[corolla]] is tubular and they are either very short or long with deeply lobed petals. The latter is the only kind of floret in the Carduoideae, while the first kind is more widespread. In the Mutisioideae disc florets are bilabiate (3+2 scheme). On the other hand, the ''ray florets'' are always highly zygomorphic and are characterised by the presence of a ''ligule''. In the Asteroideae and other minor subfamilies they are usually borne on the circumference of the capitulum and have a 3+2 scheme: three very long fused [[petal]]s form the ligule and the other two are more or less reduced. The Cichorioidea have only ray florets, which have a 5+0 scheme. The 4+1 scheme is found in the Barnadesioideae. Sometimes some marginal florets may have no petals at all (filiform floret).

The [[calyx (botany)|calyx]] of the florets is always modified into a [[pappus]] of two or more teeth, scales or bristles and is often involved in the dispersion of the seeds.

There are usually five [[stamen]]s. The filaments are fused to the corolla, while the anthers are are generally [[connation|connate]] (''syngenesious'' anthers), thus forming a sort of tube around the style (''theca''). They commonly have basal and/or apical appendages. Pollen is released inside the tube and is collected around the growing style, expelled with a sort of pump mechanism (''nüdelspritze'') or a brush.

The [[pistil]] is made of two connate [[carpel]]s. The [[carpel|style]] has two lobes, stigmatic tissue may be located in the interior surface or form two lateral lines. The [[ovary (plants)|ovary]] is inferior and has only one [[ovule]], basal [[placentation]].

=== Fruits and seeds ===
[[Image:Kih-silberdistel.jpg|thumb|250px|right|Seeds are dispersed by the wind in ''[[Carlina]]'']]
The fruit of the Asteraceae is a specialised type of [[achene]], sometimes called ''cypsela'' (plural ''cypselae''). One [[seed]] per fruit is formed. It may sometimes be flat, winged or spiny and it adheres to the persistent pappus. Its [[morphology (biology)|morphology]] is often used to help determine plant relationships at the genus and species level<ref>http://apt.allenpress.com/aptonline/?request=get-abstract&issn=0026-6493&volume=092&issue=04&page=0569</ref>. The [[seed]]s usually have little or lack [[endosperm]] <ref name="Judd"/>.

=== Metabolites ===
Asteraceae generally store energy in the form of [[inulin]].

They produce iso/chlorogenic acid, [[sesquiterpene]] [[lactones]], pentacyclic triterpene alcohols, various [[alkaloid]]s, [[acetylene]]s (cyclic, aromatic, with vinyl end groups), [[tannin]]s. They have [[terpene|terpenoid]] [[essential oils]] which never contain [[iridoid]]s <ref name="APW"/>.

== Ecology ==
[[Image:Epizoochoria NRM.jpg|thumb|200px|Epizoochory in ''[[Bidens tripartita]]'']]
Asteraceae are especially common in open and dry environments <ref name="Judd"/>.

Most Asteraceae are [[pollination|pollinated]] by insects, but [[pollination syndrome|anemophyly]] is also present (e.g. ''[[Ambrosia]]'', ''[[Artemisia]]'').

Seeds are very often dispersed by the wind (''[[Biological dispersal#wind|anemochory]]'') by mean of a hairy pappus. Another common variation is (''[[Biological dispersal#By animals|epizoochory]]''), in which the dispersal unit, a seed (e.g. ''[[Bidens]]'') or entire capitulum (e.g. ''[[Arctium]]'') provided with hooks, spines or some equivalent structure, sticks to the fur or plumage of an animal (or even to clothes, like in the photo) just to fall off later far from its mother plant.

== Evolution ==
Diversification of Asteraceae may have been within 42-36 million years, the stem group perhaps being up to 49 million years old<ref name="APW"/>.

It is still unknown whether the precise cause of their great success was the development of the calathid, their ability to store energy as [[fructan]]s (mainly [[inulin]]), which is an advantage in relatively dry zones, or some combination of these and possibly other factors<ref name="APW"/>.

==Uses==
[[Image:Field of sunflowers.JPG|thumb|left|200px|[[Sunflower]]s are a commonly cultivated member of Asteraceae]]
Commercially important plants in the Asteraceae include the food crops ''[[Lactuca sativa]]'' (lettuce), ''[[Cichorium]]'' (chicory), ''[[Cynara scolymus]]'' (globe artichoke), ''[[Helianthus annuus]]'' (sunflower), ''[[Smallanthus sonchifolius]]'' (yacón), ''[[Carthamus tinctorius]]'' (safflower) and ''[[Helianthus tuberosus]]'' (Jerusalem artichoke). The genus ''[[Artemisia]]'' includes [[absinthe]] (''A. absinthium'') and [[tarragon]] (''A. dracunculus'').

Plants in Asteraceae are medically important in that the sesquiterpene lactone compounds contained within them are an important cause of allergic contact dermatitis. Allergy to these compounds is the leading cause of allergic contact dermatitis in florists in the US.<ref>Odom & al., 2000</ref>. [[Pollen]] from ''[[Ambrosia]]'' is among the main causes of so called [[hay fever]] in the United States <ref>[http://www.aafa.org/display.cfm?id=9&sub=19&cont=267 Ragweed Allergy]</ref>.

Many members of the family are grown as ornamental plants for their flowers and some are important ornamental crops for the cut flower industry. Some examples are ''[[Chrysanthemum]]'', ''[[Gerbera]]'', ''[[Calendula]]'', ''[[Dendranthema]]'', ''[[Argyranthemum]]'', ''[[Dahlia]]'', ''[[Tagetes]]'', ''[[Zinnia]]'' and many others.
[[Image:Unidentified Pink Flower Closeup 2048px.jpg|thumb|right|200px|A ''[[Dahlia]] cultivar]]

Many members of Asteraceae are copious [[nectar (plant)|nectar]] producers and are useful for evaluating [[pollinator]] populations during their bloom. ''[[Centaurea]]'' (knapweed), ''[[Helianthus annuus]]'' (domestic sunflower), and some species of ''[[Solidago]]'' (goldenrod) are major "[[honey]] plants" for [[beekeeper]]s. ''Solidago'' produces relatively high protein [[pollen]], which helps [[honey bee]]s overwinter {{Fact|date=November 2007}}.

Some members of the Asteraceae are important as weeds, like ''[[Senecio jacobaea]]'' (ragwort), ''[[Senecio vulgaris]]'' (groundsel) and ''[[Taraxacum]]'' (dandelion).

''[[Tanacetum]]'' and ''[[Pulicaria]]'' contain plants with insecticidal properties.

''[[Parthenium argentatum]]'' (Guayule) is a source of [[hypoallergenic]] [[latex]].

==Genera==
{{main|List of Asteraceae genera}}


==Image gallery==
<gallery>
Image:Golden Ragwort Senecio aureus Flowers 2616px.jpg|''[[Senecio aureus]]''
Image:Vernonia fasciculata.jpg|''[[Vernonia fasciculata]]''
Image:Koninginnenkruid A.jpg|''[[Eupatorium cannabinum]]''
Image:Chuquiraga oppositifolia.jpg|''[[Chuquiraga oppostifolia]]'' (Barnadesioideae)
Image:Carduus tenuiflorus1.jpg|''[[Carduus tenuiflorus]]'' (Carduoideae)
Image:Big yellow.jpg|''[[Gerbera]] sp.'' (Mutisoideae). Note the zygomorphic disc flowers.
Image:Pertya scandens2.jpg|''[[Pertya scandens]]'' (Pertyoideae)
Image:Cichorium intybus-alvesgaspar1.jpg|''[[Cichorium intybus]]'' (Cichorioideae). Note the dark blue anther tubes and the bilabiate styles.
Image:399px-IMG 5243aw.jpg|''[[Aster novae-angliae]] (Asteroideae)
Image:Ray.floret01.jpg|Ray floret (as in Chichorioideae)
Image:Disc floret01.jpg|Disc floret (as in Asteroideae)
Image:Artichaut2.jpg|The involucral leaves of the capitula of the [[globe artichoke]] (here flowering) are eaten as vegetable
Image:Tragopogon pratensis-Ejdzej-2006-B.jpg|The large seed head of ''[[Tragopogon pratensis]]'' is composed of many single achenes, each with its own pappus
Image:Bidens_dentes_NRM.jpg|Sticking teeth of a ''Bidens tripartita'' achene under stereomicroscope (30X).
Image:Taraxacum sect Ruderalia10 ies.jpg|The stem of the [[dandelion]] (''Taraxacum'', Cichorioidea) contains a bitter [[latex]].
</gallery>

== Footnotes ==
{{reflist}}

== References ==
*Stevens, P. F. ''Angiosperm Phylogeny Website''
*{{cite book |last= Usher|first= George|title= A dictionary of botany, including terms used in bio-chemistry, soil science, and statistics|year= 1966|publisher= Van Nostrand|location= Princeton|id= {{LCCN|66|0|25447}}}}
* Judd & al. ''Plant Systematics: A Phylogenetic Approach
*http://ibot.sav.sk/icbn/main.htm International Code of Botanical Nomenclature (VIENNA CODE)
* [http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=35420 ITIS report 2002-09-10]
* Walters, Dirk R. and David J. Keil (1996). ''Vascular plant taxonomy''. 4th ed. Kendall/Hunt Publishing Company. Dubuque, Iowa.
* Wagner,W.L., D.R. Herbst, and S.H. Sohmer. 1990. ''Manual of the Flowering Plants of Hawai‘i'', Vol. I. University of Hawaii Press, Honolulu. 988 pp.
* D. J. N. Hind, C. Jeffrey & G. V. Pope (eds.), Advances in Compositae systematics. - Royal Bot. Gardens, Kew, 469 pp., 1995
*{{cite book | title=Andrews' Diseases of the Skin: Clinical Dermatology| last=Odom| first=Richard B.| coauthors=William D. James, Timothy G. Berger| date=2000| pages=1135 pages| publisher=W.B. Saunders Company| id=ISBN 0721658326}}
==External links==
{{commonscat|Asteraceae}}
{{Wikispecies|Asteraceae}}
* {{dmoz|/Science/Biology/Flora_and_Fauna/Plantae/Magnoliophyta/Magnoliopsida/Asteraceae/}}

[[Category:Plant families]]
[[Category:Asteraceae]]

[[bg:Сложноцветни]]
[[ca:Asteràcia]]
[[cs:Hvězdnicovité]]
[[da:Kurvblomst-familien]]
[[de:Korbblütler]]
[[et:Korvõielised]]
[[es:Asteraceae]]
[[eo:Asteracoj]]
[[fa:گل‌ستاره‌ای‌ها]]
[[fr:Asteraceae]]
[[ko:국화과]]
[[is:Körfublómaætt]]
[[it:Asteraceae]]
[[he:מורכבים]]
[[la:Asteraceae]]
[[lt:Astriniai]]
[[hu:Fészkesek]]
[[nl:Composietenfamilie]]
[[ja:キク科]]
[[no:Kurvplantefamilien]]
[[nn:Korgplantefamilien]]
[[pl:Astrowate]]
[[pt:Asteraceae]]
[[ro:Asteraceae]]
[[qu:Ch'antasqa tuktuyuq rikch'aq ayllu]]
[[ru:Сложноцветные]]
[[scn:Asteraceae]]
[[sl:Nebinovke]]
[[fi:Asterikasvit]]
[[sv:Korgblommiga växter]]
[[te:ఆస్టరేసి]]
[[vi:Họ Cúc]]
[[tr:Papatyagiller]]
[[uk:Айстрові]]
[[ur:نجمان]]
[[wa:Stoelacêyes]]
[[bat-smg:Astrinē]]
[[zh:菊科]]