84-545: Asteraceae ( / ˌ æ s t ə ˈ r eɪ s i . iː , - ˌ aɪ / ) is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales . The number of species in Asteraceae is rivaled only by the Orchidaceae , and which is the larger family is unclear as the quantity of extant species in each family is unknown. The Asteraceae were first described in
168-473: A sonicating bee (one that vibrates its wing muscles while perched on the flower), such as a bumblebee. Sonicating bees are extremely efficient pollinators of tomatoes, and colonies of bumblebees are quickly replacing humans as the primary pollinators for greenhouse tomatoes. Pollinators require a variety of resources. Most native bees in North America are solitary, ground-nesting species that collect
252-510: A " celestial body with rays". The capitulum, which often appears to be a single flower, is often referred to as a head . In some species, the entire head is able to pivot its floral stem in the course of the day to track the sun (like a "smart" solar panel), thus maximizing the reflectivity of the entire floral unit and further attracting flying pollinators. Nearest to the flower stem lie a series of small, usually green, scale-like bracts . These are known as phyllaries ; collectively, they form
336-513: A 3+2 scheme – above the fused corolla tube, three very long fused petals form the ligule, with the other two petals being inconspicuously small. The Cichorioideae has only ray florets, with a 5+0 scheme – all five petals form the ligule. A 4+1 scheme is found in the Barnadesioideae. The tip of the ligule is often divided into teeth, each one representing a petal. Some marginal florets may have no petals at all (filiform floret). The calyx of
420-602: A comprehensive approach to tackling and reducing the impact of multiple stressors on pollinator health, including pests and pathogens, reduced habitat, lack of nutritional resources, and exposure to pesticides. The national strategy laid out federal actions to achieve three goals: Many of the priority projects that the national strategy identified focused on the I-35 corridor, which extends for 1,500 miles (2,400 km) from Texas to Minnesota. The area through which that highway travels provides spring and summer breeding habitats in
504-442: A critical point. This simultaneous collapse occurs, because pollinator species depend on each other when surviving under difficult conditions. Such a community-wide collapse, involving many pollinator species, can occur suddenly when increasingly harsh conditions pass a critical point and recovery from such a collapse might not be easy. The improvement in conditions needed for pollinators to recover, could be substantially larger than
588-502: A fetid odor . The plants' ecological strategy varies; several species of Stapelia , for example, attract carrion flies that futilely lay their eggs on the flower, where their larvae promptly starve for lack of carrion . Other species do decay rapidly after ripening, and offer the visiting insects large masses of food, as well as pollen and sometimes seed to carry off when they leave. Hoverflies are important pollinators of flowering plants worldwide. Often hoverflies are considered to be
672-445: A few unusual species, the "head" will consist of one single disc flower; alternatively, a few species will produce both single-flowered female heads, along with multi-flowered male heads, in their "pollination strategy". The distinguishing characteristic of Asteraceae is their inflorescence , a type of specialised, composite flower head or pseudanthium , technically called a calathium or capitulum , that may look superficially like
756-553: A key ecosystem service vital to the maintenance of both wild and agricultural plant communities. In 1999 the Convention on Biological Diversity issued the São Paulo Declaration on Pollinators, recognizing the critical role that these species play in supporting and maintaining terrestrial productivity as well as the survival challenges they face due to anthropogenic change. Today pollinators are considered to be in
840-554: A lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching a consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called
924-549: A mud chamber prior to oviposition. Also, males of many species of bees and wasps, though they do not gather pollen, rely on flowers as sources of energy (in the form of nectar) and also as territories for meeting fertile females that visit the flowers. Some Diptera (flies) may be the main pollinators at higher elevations of mountains, whereas bumblebee species are typically the only other pollinators in alpine regions at timberline and beyond. Some adult mosquitoes , if they feed on nectar, may act as pollinators; Aedes communis ,
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#17327729576921008-401: A network of interactions between plants and pollinators. Surprising similarities were found in the structure of networks consisting out of the interactions between plants and pollinators. This structure was found to be similar in very different ecosystems on different continents, consisting of entirely different species. The structure of plant-pollinator networks may have large consequences for
1092-408: A particular hawk moth , Morgan's sphinx . Yucca species provide other examples, being fertilised in elaborate ecological interactions with particular species of yucca moths . Many bee flies , and some Tabanidae and Nemestrinidae are particularly adapted to pollinating fynbos and Karoo plants with narrow, deep corolla tubes , such as Lapeirousia species. Part of the adaptation takes
1176-893: A preliminary project in Chile, the program has expanded to Colombia, Argentina, and Costa Rica. The ‘Coalition of the Willing on Pollinators' (Promote Pollinators) was initiated in 2016 during the Convention on Biological Diversity's Conference of the Parties (CBD COP13) and is a growing alliance of countries and observers who support the notion that country-led politics can lead to policy measures and innovative action to protect pollinators'. Their supporters are growing steadily, in which 30 countries currently participate. Wild pollinators often visit many plant species and plants are visited by many pollinator species. All these relations together form
1260-428: A scarious (dry and membranous) texture. The phyllaries can be free or fused, and arranged in one to many rows, overlapping like the tiles of a roof ( imbricate ) or not (this variation is important in identification of tribes and genera). Each floret may be subtended by a bract, called a "palea" or "receptacular bract". These bracts are often called " chaff ". The presence or absence of these bracts, their distribution on
1344-478: A single floral entity is in fact a composite of much smaller flowers. The "petals" or "sunrays" in an "asteraceous" head are in fact individual strap-shaped flowers called ray flowers or ray florets , and the "sun disk" is made up of smaller, radially symmetric , individual flowers called disc flowers or disc florets . The word aster means "star" in Greek, referring to the appearance of most family members as
1428-441: A single flower. The capitulum is a contracted raceme composed of numerous individual sessile flowers , called florets , all sharing the same receptacle . A set of bracts forms an involucre surrounding the base of the capitulum. These are called "phyllaries", or "involucral bracts". They may simulate the sepals of the pseudanthium. These are mostly herbaceous but can also be brightly coloured (e.g. Helichrysum ) or have
1512-420: 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, and then, as the style elongates, is pushed out of the tube ( nüdelspritze ). The pistil consists of two connate carpels . The style has two lobes. Stigmatic tissue may be located in the interior surface or form two lateral lines. The ovary
1596-710: A species found in North America, is known to pollinate Platanthera obtusata , commonly referred as the blunt-leaved orchid. Beetles of species that specialise in eating pollen, nectar, or flowers themselves, may be important cross-pollinators of some plants such as members of the Araceae and Zamiaceae , that produce prodigious amounts of pollen. Others, for example the Hopliini , specialise on flowers of Asteraceae and Aizoaceae . Minute midges and flower- thrips can occur in vast numbers, moving between flowers and plant individuals, enabling some species to contribute to
1680-575: A state of decline; some species, such as Franklin's bumble bee ( Bombus franklini ) have been red-listed and are in danger of extinction. Although managed bee hives are increasing worldwide, these can not compensate for the loss of wild pollinators in many locations. A 2017 report done for the Center of Biological Diversity utilized data documented in the United States on native bee species and found that nearly 1 in 4 (347 species of 1,437 species)
1764-532: A stem node age of 88–89 mya (Late Cretaceous, Coniacian ). Asteraceae is an economically important family, providing food staples, garden plants, and herbal medicines. Species outside of their native ranges can become weedy or invasive . Members of the Asteraceae are mostly herbaceous plants, but some shrubs, vines, and trees (such as Lachanodes arborea ) do exist. Asteraceae species are generally easy to distinguish from other plants because of their unique inflorescence and other shared characteristics, such as
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#17327729576921848-433: A strain genetically pure. This can involve using a small brush or cotton swab to move pollen, or to simply tap or shake tomato blossoms to release the pollen for the self-pollinating flowers. Tomato blossoms are self-fertile, but (with the exception of potato-leaf varieties) have the pollen inside the anther , and the flower requires shaking to release the pollen through pores . This can be done by wind, by humans, or by
1932-419: A threat to the economic stability of commercial beekeeping and pollination operations in the United States, which could have profound implications for agriculture and food. Severe yearly declines create concern that bee colony losses could reach a point from which the commercial pollination industry would not be able to adequately recover. The loss of native bees, which also play a key role in pollination of crops,
2016-711: A variety of natural resources including pollen, nectar, leaves, petals and resins to be used as sources of food, supplies for their larva, or nest linings. Floral diet diversity has been seen to increase immunocompetence levels in honeybees (Apis mellifera) where diets that consisted of a wide variety of flowering species induced higher glucose oxidase activity, which honeybees' produce to sterilize their colony. More than 30% of global bee species depend on non-floral resources for nest building, protection, health, pest resistance, and alternative food sources. Non-floral resources include leaves, soil, plant resins and secretions, and are often provided by woody-vegetation. Pollinators provide
2100-618: Is a collaboration between the Bayer Bee Care Center and the Fraunhofer Chile Research Foundation, that works alongside local researchers at universities and beekeepers' associations. The program focuses on increasing the number of healthy worker bees and their colonies by monitoring honey bee health and the contributing factors. This includes educating beekeepers and research collaborations to jointly work on honey bee health. Founded in 2015 with
2184-412: Is a two- or three-lobed, strap-shaped, individual flower, found in the head of most members of the Asteraceae. The corolla of the ray flower may have two tiny, vestigial teeth, opposite to the three-lobed strap, or tongue, indicating its evolution by fusion from an ancestral, five-part corolla. In some species, the 3:2 arrangement is reversed, with two lobes, and zero or three tiny teeth visible opposite
2268-411: Is actually a composite of several much smaller flowers, known as the capitulum or head . By visually presenting as a single flower, the capitulum functions in attracting pollinators , in the same manner that other "showy" flowering plants in numerous other, older, plant families have evolved to attract pollinators. The previous name for the family, Compositae , reflects the fact that what appears to be
2352-538: Is an advantage in relatively dry zones, or some combination of these and possibly other factors. Heterocarpy, or the ability to produce different fruit morphs, has evolved and is common in Asteraceae. It allows seeds to be dispersed over varying distances and each is adapted to different environments, increasing chances of survival. The original name Compositae is still valid under the International Code of Nomenclature for algae, fungi, and plants. It refers to
2436-1384: Is based on Panero & Funk (2002) updated in 2014, and now also includes the monotypic Famatinanthoideae . The diamond (♦) denotes a very poorly supported node (<50% bootstrap support), the dot (•) a poorly supported node (<80%). Barnadesioideae : 9 genera, 93 species. South America , mainly the Andes . Famatinanthoideae : South America, 1 genus, 1 species Famatinanthus decussatus . Mutisioideae : 58 genera, 750 species. Absent from Europe, mostly in South America. Stifftioideae : 10 genera. South America. Wunderlichioideae : 8 genera, 24 species. Mostly in Venezuela and Guyana . Gochnatioideae : 4 or 5 genera, 90 species. Latin America and southern United States. Hecastocleidoideae : Only Hecastocleis shockleyi . Southwestern United States . Carduoideae : 83 genera, 2,500 species. Worldwide. Pertyoideae : 5 or 6 genera, 70 species. Asia. Gymnarrhenoideae : Two genera/species, Gymnarrhena micrantha ( Northern Africa , Middle East ) and Cavea tanguensis ( Eastern Himalayas ). Cichorioideae : 224 genera, 3,200 species. Worldwide. Corymbioideae : Only
2520-533: Is compound flower heads , technically known as capitula , consisting of sometimes hundreds of tiny individual florets enclosed by a whorl of protective involucral bracts . The oldest known fossils are pollen grains from the Late Cretaceous ( Campanian to Maastrichtian ) of Antarctica, dated to c. 76–66 million years ago (mya). It is estimated that the crown group of Asteraceae evolved at least 85.9 mya (Late Cretaceous, Santonian ) with
2604-565: Is developing strategic plans for conservation that looks to establish partnership between government entities. 11 pollinator-protection agreements have been signed between NAPCC and federal government agencies, responsible for more than 1.5 billion acres of land protections and management. Along with the European Green Deal , which contains initiatives that support pollinator populations, the European Union has implemented
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2688-532: Is high protein food, to nurture their young, and transfer some among the flowers as they are working. Euglossine bees pollinate orchids, but these are male bees collecting floral scents rather than females gathering nectar or pollen. Female orchid bees act as pollinators, but of flowers other than orchids. Eusocial bees such as honey bees need an abundant and steady pollen source to multiply. Honey bees travel from flower to flower, collecting nectar (later converted to honey ), and pollen grains. The bee collects
2772-702: Is imperiled and at increasing risk of extinction. More than half of the native bee species is in decline and 40% of global insect pollinators (primarily native bees) are highly threatened. Declines in the health and population of pollinators pose what could be a significant threat to the integrity of biodiversity, to global food webs, and to human health. At least 80% of our world's crop species require pollination to set seed. A 2021 study estimated that without pollinators, fertility would be reduced by 80% in half all wild plant species and one-third of all wild plant species would fail to produce any seeds at all. An estimated one out of every three bites of food comes to us through
2856-449: Is inferior and has only one ovule , with basal placentation . In members of the Asteraceae the fruit is achene -like, and is called a cypsela (plural cypselae ). Although there are two fused carpels, there is only one locule, and only one seed per fruit is formed. It may sometimes be winged or spiny because the pappus, which is derived from calyx tissue often remains on the fruit (for example in dandelion ). In some species, however,
2940-596: Is much less studied, but many native bee species are believed to be in decline. Scientists believe that bee losses are likely caused by a combination of stressors, including poor bee nutrition, loss of forage lands, parasites, pathogens, lack of genetic diversity, and exposure to pesticides. In May 2015, the Pollinator Health Task Force issued a "National Strategy to Promote the Health of Honey Bees and Other Pollinators". The national strategy outlined
3024-798: Is that of sexual deception, where plants, generally orchids, produce remarkably complex combinations of pheromonal attractants and physical mimicry that induce male bees or wasps to attempt to mate with them, conveying pollinia in the process. Examples are known from all continents apart from Antarctica , though Australia appears to be exceptionally rich in examples. Whole groups of plants, such as certain fynbos Moraea and Erica species produce flowers on sticky peduncles or with sticky corolla tubes that only permit access to flying pollinators, whether bird, bat, or insect. Experimental evidence has shown invertebrates (mostly small crustaceans ) acting as pollinators in underwater environments. Beds of seagrass have been shown to reproduce this way in
3108-524: Is the only kind of floret in the Carduoideae , while the first kind is more widespread. Ray florets are always highly zygomorphic and are characterised by the presence of a ligule , a strap-shaped structure on the edge of the corolla tube consisting of fused petals. In the Asteroideae and other minor subfamilies these are usually borne only on florets at the circumference of the capitulum and have
3192-481: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Pollinators A pollinator is an animal that moves pollen from
3276-613: The Environmental Protection Agency to ban neonicotinoids , a type of insecticide. On June 20, 2014, President Barack Obama issued a presidential memorandum entitled "Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators". The President's memorandum established a Pollinator Health Task Force, to be co-chaired by the Secretary of Agriculture and the Administrator of
3360-448: The innate yellow colour preference of syrphids. Some male dacine fruit flies are exclusive pollinators of some wild Bulbophyllum orchids that lack nectar and have a specific chemical attractant and reward (methyl eugenol, raspberry ketone or zingerone) present in their floral fragrances. Many insects other than bees accomplish pollination by visiting flowers for nectar or pollen, or commonly both. Many do so adventitiously, but
3444-428: The involucre , which serves to protect the immature head of florets during its development. The individual florets are arranged atop a dome-like structure called the receptacle . The individual florets in a head consist, developmentally, of five fused petals (rarely four); instead of sepals , they have threadlike, hairy, or bristly structures, known collectively as a pappus , (plural pappi ). The pappus surrounds
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3528-620: The "composite" nature of the capitula, which consist of a few or many individual flowers. Family (biology) Family ( Latin : familia , pl. : familiae ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to
3612-753: The Americas and Australia historically has been performed by various native bees. It has also been found that non-native plants may have positive effects on native bee pollinators while also influencing their foraging patterns and bee–plant networks. Lepidoptera ( butterflies and moths ) may also pollinate to various degrees. They are not major pollinators of food crops , but various moths are important pollinators of other commercial crops such as tobacco . Pollination by certain moths may be important, however, or even crucial, for some wildflowers mutually adapted to specialist pollinators. Spectacular examples include orchids such as Angraecum sesquipedale , dependent on
3696-647: The EU Biodiversity Strategy for 2030 which includes the EU Pollinators Initiative that sets long-term objectives to reverse pollinator decline in diversity and numbers by 2030. This initiative includes: (1) improving knowledge of pollinator decline, its causes and consequences; (2) tackling the causes of pollinator decline; and (3) raising awareness, engaging society-at-large and promoting collaboration. The Healthy Hives Latin America 2020 (Salud Apícola 2020 Latinoamérica) program
3780-555: The Environmental Protection Agency . The memorandum stated: Pollinators contribute substantially to the economy of the United States and are vital to keeping fruits, nuts, and vegetables in our diets. Honey bee pollination alone adds more than $ 15 billion in value to agricultural crops each year in the United States. Over the past few decades, there has been a significant loss of pollinators, including honey bees, native bees, birds, bats, and butterflies, from
3864-613: The Task Force issued a "Pollinator Partnership Action Plan". That Plan provided examples of past, ongoing, and possible future collaborations between the federal government and non-federal institutions to support pollinator health under each of the national strategy's goals. The North American Pollinator Protection Campaign (NAPPC) aims to promote pollinator health across the North America and has organized annual conferences since 1997, creates task forces to implement specific objectives that includes public education and policy research, and
3948-442: The United States' key monarch migration corridor. The Pollinator Health Task Force simultaneously issued a "Pollinator Research Action Plan". The Plan outlined five main action areas, covered in ten subject-specific chapters. The action areas were: (1) Setting a Baseline; (2) Assessing Environmental Stressors; (3) Restoring Habitat; (4) Understanding and Supporting Stakeholders; (5) Curating and Sharing Knowledge. In June 2016,
4032-805: The absence of currents. It is not yet known how important invertebrate pollinators might be for other species. Later, Idotea balthica was discovered to help Gracilaria gracilis reproduce – the first known case of an animal helping algae reproduce. Bats are important pollinators of some tropical flowers, visiting to take nectar. Birds, particularly hummingbirds , honeyeaters and sunbirds also accomplish much pollination, especially of deep-throated flowers. Other vertebrates , such as kinkajous , monkeys , lemurs , possums , rodents and lizards have been recorded pollinating some plants. Humans can be pollinators, as many gardeners have discovered that they must hand pollinate garden vegetables , whether because of pollinator decline or simply to keep
4116-612: The authors. Neonicotinoids (Neonics) are a class of synthetic insecticides that are the most widely applied pesticides today due to its water solubility and ability to treat a wide variety of pests. Neonics are highly environmentally persistent, and may contaminate terrestrial and aquatic habitats for as much as six years. Exposed honeybees' (Apis mellifera) have been seen to have lower reproductive output, reduction in nest building or failed to build nests, reduced foraging abilities, and weakened immunity. Researchers are still trying to determine how to scientifically best restore and maintain
4200-774: The depth and width of the corolla, the color (including patterns called nectar guides that are visible only in ultraviolet light), the scent , amount of nectar, composition of nectar, etc. For example, birds visit red flowers with long, narrow tubes and much nectar, but are not as strongly attracted to wide flowers with little nectar and copious pollen, which are more attractive to beetles. When these characteristics are experimentally modified (altering colour, size, orientation), pollinator visitation may decline. Although non-bee pollinators have been seen to be less effective at depositing pollen than bee pollinators one study showed that non-bees made more visits than bees resulting in non-bees performing 38% of visits to crop flowers, outweighing
4284-624: The disc in irregular symmetry, or with a weakly bilaterally symmetric arrangement. A radiate head has disc flowers surrounded by ray flowers. A ligulate head has all ligulate flowers and no disc flowers. When an Asteraceae flower head has only disc flowers that are either sterile, male, or bisexual (but not female and fertile), it is a discoid head . Disciform heads possess only disc flowers in their heads, but may produce two different sex types (male or female) within their disciform head. Some other species produce two different head types: staminate (all-male), or pistillate (all-female). In
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#17327729576924368-705: The diverse pollinator habitats found around the world. Many studies conclude that restoration and conservation are key to maintaining biodiversity and pollinator populations. According to the Kansas National Park Service, native tallgrass prairie was widespread through North America and home to over 300 species of flowering plants. This habitat is crucial to wild pollinators and now only covers 4% of its original 170-million acre range. By restoring wild pollinators natural habitat and maintaining Earth's biodiversity, populations are assumed to increase. In recent times, environmental groups have put pressure on
4452-611: The energy store is generally in the form of inulin rather than starch. They produce iso/ chlorogenic acid , sesquiterpene lactones , pentacyclic triterpene alcohols, various alkaloids , acetylenes (cyclic, aromatic, with vinyl end groups), tannins . They have terpenoid essential oils that never contain iridoids . Asteraceae produce secondary metabolites , such as flavonoids and terpenoids . Some of these molecules can inhibit protozoan parasites such as Plasmodium , Trypanosoma , Leishmania and parasitic intestinal worms, and thus have potential in medicine. Compositae,
4536-489: The environment. The problem is serious and requires immediate attention to ensure the sustainability of our food production systems, avoid additional economic impact on the agricultural sector, and protect the health of the environment. Pollinator losses have been severe. The number of migrating Monarch butterflies sank to the lowest recorded population level in 2013-14, and there is an imminent risk of failed migration. The continued loss of commercial honey bee colonies poses
4620-421: The extant genus Dasyphyllum . Barreda, et al. (2015) estimated that the crown group of Asteraceae evolved at least 85.9 mya (Late Cretaceous, Santonian ) with a stem node age of 88–89 mya (Late Cretaceous, Coniacian ). It is not known whether the precise cause of their great success was the development of the highly specialised capitulum, their ability to store energy as fructans (mainly inulin ), which
4704-542: The family Juglandaceae , but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to
4788-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and
4872-424: The florets may be absent, but when present is always modified into a pappus of two or more teeth, scales or bristles and this is often involved in the dispersion of the seeds. As with the bracts, the nature of the pappus is an important diagnostic feature. There are usually four or five stamens . The filaments are fused to the corolla, while the anthers are generally connate ( syngenesious anthers), thus forming
4956-425: The form of a structure known as the scopa , which is on the hind legs of most bees, and/or the lower abdomen (e.g., of megachilid bees), made up of thick, plumose setae . Honey bees , bumblebees , and their relatives do not have a scopa, but the hind leg is modified into a structure called the corbicula (also known as the " pollen basket "). Most bees gather nectar , a concentrated energy source, and pollen, which
5040-405: The form of remarkably long probosces. This also applies to empidine dance flies ( Empidinae ) that visit a wide range of flowering plants, some species of which can pollinate the woodland geranium ( Geranium sylvaticum L. ) as effectively as bees . Carrion flies and flesh flies in families such as Calliphoridae and Sarcophagidae are important for some species of plants whose flowers exude
5124-544: The genus Corymbium , with 9 species. Cape provinces, South Africa. Asteroideae : 1,130 genera and 16,200 species. Worldwide. The family includes over 32,000 currently accepted species, in over 1,900 genera ( list ) in 13 subfamilies. The number of species in the family Asteraceae is rivaled only by Orchidaceae. Which is the larger family is unclear, because of the uncertainty about how many extant species each family includes. The four subfamilies Asteroideae , Cichorioideae , Carduoideae and Mutisioideae contain 99% of
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#17327729576925208-603: The ineffectiveness of their ability to pollinate. It has recently been discovered that cycads , which are not flowering plants , are also pollinated by insects. In 2016, researchers showed evidence of pollination occurring underwater, which was previously thought not to happen. The most recognized pollinators are the various species of bees , which are plainly adapted to pollination. Bees typically are fuzzy and carry an electrostatic charge. Both features help pollen grains adhere to their bodies, but they also have specialized pollen-carrying structures; in most bees, this takes
5292-422: The joined anthers of the stamens . Nonetheless, determining genera and species of some groups such as Hieracium is notoriously difficult (see " damned yellow composite " for example). Members of the family Asteraceae generally produce taproots , but sometimes they possess fibrous root systems. Some species have underground stems in the form of caudices or rhizomes . These can be fleshy or woody depending on
5376-423: The leaves. Nearly all Asteraceae bear their flowers in dense flower heads called capitula . They are surrounded by involucral bracts , and when viewed from a distance, each capitulum may appear to be a single flower. Enlarged outer (peripheral) flowers in the capitulum may resemble petals, and the involucral bracts may look like a calyx. In plants of the Asteraceae, what appears to be a single "daisy"-type flower
5460-611: The male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are the major pollinators of most plants, and insect pollinators include all families of bees and most families of aculeate wasps ; ants ; many families of flies ; many lepidopterans (both butterflies and moths ); and many families of beetles . Vertebrates, mainly bats and birds, but also some non-bat mammals ( monkeys , lemurs , possums , rodents ) and some lizards pollinate certain plants. Among
5544-479: The most important commercial pollinating agents, but many other kinds of pollinators, from blue bottle flies, to bumblebees, orchard mason bees , and leaf cutter bees are cultured and sold for managed pollination . Other species of bees differ in various details of their behavior and pollen-gathering habits, and honey bees are not native to the Western Hemisphere ; all pollination of native plants in
5628-640: The most important pollinators are specialists for at least parts of their life cycles for at least certain functions. Prominent among Hymenoptera other than bees are predatory aculeate wasps (especially Crabronidae , Sphecidae , Vespidae , and Pompilidae ). The term " pollen wasps ", in particular, is widely applied to the Masarinae, a subfamily of the Vespidae; they are remarkable among solitary wasps in that they specialise in gathering pollen for feeding their larvae, carried internally and regurgitated into
5712-527: The nutritional needs of the brood. Good pollination management seeks to have bees in a "building" state during the bloom period of the crop, thus requiring them to gather pollen, and making them more efficient pollinators. Thus, the management techniques of a beekeeper providing pollination services are different from, and to some extent in tension with, those of a beekeeper who is trying to produce honey. Millions of hives of honey bees are contracted out as pollinators by beekeepers , and honey bees are by far
5796-467: The original name for Asteraceae, were first described in 1740 by Dutch botanist Adriaan van Royen . Traditionally, two subfamilies were recognised: Asteroideae (or Tubuliflorae) and Cichorioideae (or Liguliflorae). The latter has been shown to be extensively paraphyletic , and has now been divided into 12 subfamilies, but the former still stands. The study of this family is known as synantherology . The phylogenetic tree of subfamilies presented below
5880-433: The ovary and can, when mature and attached to a seed, adhere to animal fur or be carried by air currents, aiding in seed dispersal . The whitish, fluffy head of a dandelion , commonly blown on by children, consists of numerous seeds resting on the receptacle, each seed attached to its pappus. The pappi provide a parachute-like structure to help the seed travel from its point of origin to a more hospitable site. A ray flower
5964-468: The pappus falls off (for example in Helianthus ). Cypsela morphology is often used to help determine plant relationships at the genus and species level. The mature seeds usually have little endosperm or none. The pollen of composites is typically echinolophate, a morphological term meaning "with elaborate systems of ridges and spines dispersed around and between the apertures." In Asteraceae,
6048-453: The pollen by rubbing against the anthers. The pollen collects on the hind legs, in a structure referred to as a "pollen basket". As the bee flies from flower to flower, some of the pollen grains are transferred onto the stigma of other flowers. Nectar provides the energy for bee nutrition ; pollen provides the protein . When bees are rearing large quantities of brood (beekeepers say hives are "building"), bees deliberately gather pollen to meet
6132-456: The pollinating birds are hummingbirds , honeyeaters and sunbirds with long beaks; they pollinate a number of deep-throated flowers. Humans may also carry out artificial pollination . A pollinator is different from a pollenizer , a plant that is a source of pollen for the pollination process. Plants fall into pollination syndromes that reflect the type of pollinator being attracted. These are characteristics such as: overall flower size,
6216-487: The pollination of tree-crops such as cacao, Theobroma cacao L. (Malvaceae) and elderflower Sambucus nigra L. (Adoxaceae). Ants also pollinate some kinds of flowers, but for the most part they are parasites, consuming nectar and/or pollen without conveying useful amounts of pollen to a stigma. Other insect orders are rarely pollinators, and then typically only incidentally (e.g., Hemiptera such as Anthocoridae and Miridae ). A strategy of great biological interest
6300-440: The receptacle, and their size and shape are all important diagnostic characteristics for genera and tribes. The florets have five petals fused at the base to form a corolla tube and they may be either actinomorphic or zygomorphic . Disc florets are usually actinomorphic, with five petal lips on the rim of the corolla tube. The petal lips may be either very short, or long, in which case they form deeply lobed petals. The latter
6384-421: The second most important pollinators after wild bees. Although hoverflies as a whole are generally considered to be nonselective pollinators, some species have more specialized relationships. The orchid species Epipactis veratrifolia mimics alarm pheromones of aphids to attract hover flies for pollination. Another plant, the slipper orchid in southwest China, also achieves pollination by deceit by exploiting
6468-575: The seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted
6552-497: The species diversity of the whole family (approximately 70%, 14%, 11% and 3% respectively). Because of the morphological complexity exhibited by this family, agreeing on generic circumscriptions has often been difficult for taxonomists . As a result, several of these genera have required multiple revisions. The oldest known fossils of members of Asteraceae are pollen grains from the Late Cretaceous of Antarctica , dated to ~76–66 mya ( Campanian to Maastrichtian ) and assigned to
6636-578: The species. The stems are herbaceous, aerial, branched, and cylindrical with glandular hairs, usually erect, but can be prostrate to ascending. The stems can contain secretory canals with resin , or latex , which is particularly common among the Cichorioideae . Leaves can be alternate , opposite , or whorled . They may be simple , but are often deeply lobed or otherwise incised, often conduplicate or revolute . The margins also can be entire or toothed . Resin or latex can also be present in
6720-440: The tongue. A ligulate flower is a five-lobed, strap-shaped, individual flower found in the heads of certain other asteraceous species. A ligule is the strap-shaped tongue of the corolla of either a ray flower or of a ligulate flower. A disk flower (or disc flower ) is a radially symmetric individual flower in the head, which is ringed by the ray flowers when both are present. In some species, ray flowers may be arranged around
6804-549: The use of this term solely within the book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,
6888-581: The way in which pollinator communities respond to increasingly harsh conditions. Mathematical models, examining the consequences of this network structure for the stability of pollinator communities suggest that the specific way in which plant-pollinator networks are organized minimizes competition between pollinators and may even lead to strong indirect facilitation between pollinators when conditions are harsh. This allows pollinator species to survive together under harsh conditions. But it also means that pollinator species collapse simultaneously when conditions pass
6972-514: The work of animal pollinators. The quality of pollinator service has declined over time and this had led to concerns that pollination will be less resistant to extinction in the future. A 2022 study concludes that the decline of pollinator populations is responsible for 500,000 early human deaths per year by reducing the supply of healthy foods. A decline of pollinators has caused 3-5% loss of fruits, vegetables and nuts. Lower consumption of these healthy foods translates to 1% of all deaths, according to
7056-571: The year 1740 and given the original name Compositae . The family is commonly known as the aster , daisy , composite , or sunflower family . Most species of Asteraceae are herbaceous plants , and may be annual , biennial , or perennial , but there are also shrubs , vines , and trees . The family has a widespread distribution, from subpolar to tropical regions , in a wide variety of habitats. Most occur in hot desert and cold or hot semi-desert climates , and they are found on every continent but Antarctica . Their common primary characteristic
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