Asterales () is an order of dicotyledonous

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 ...

s that includes the large

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

(or Compositae) known for composite flowers made of

florets This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

, and ten families related to the Asteraceae. While

asterids In the APG IV system (2016) for the classification of flowering plants, the name asterids denotes a clade (a monophyletic group). Asterids is the largest group of flowering plants, with more than 80,000 species, about a third of the total flowe ...

in general are characterized by fused petals, composite flowers consisting of many florets create the false appearance of separate petals (as found in the

rosids The rosids are members of a large clade (monophyletic group) of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classificati ...

). The order is

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

(plants found throughout most of the world including desert and frigid zones), and includes mostly

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

species, although a small number of trees (such as the ''

Lobelia deckenii ''Lobelia deckenii'' is a species of flowering plant in the family Campanulaceae. It is a giant lobelia endemic to the mountains of Tanzania. It is listed as a threatened plant of the Cherangani Hills Forest, forests of Cherangani hills, Kenya. I ...

'', the giant lobelia, and ''

Dendrosenecio ''Dendrosenecio'' is a genus of flowering plants in the sunflower family. It is a segregate of ''Senecio'', in which it formed the subgenus ''Dendrosenecio''. Its members, the giant groundsels, are native to the higher altitude zones of ten mo ...

'', giant groundsels) and

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s are also present. Asterales are organisms that seem to have evolved from one common

ancestor An ancestor, also known as a forefather, fore-elder or a forebear, is a parent or (recursively) the parent of an antecedent (i.e., a grandparent, great-grandparent, great-great-grandparent and so forth). ''Ancestor'' is "any person from whom ...

. Asterales share characteristics on morphological and biochemical levels.

Synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

(a character that is shared by two or more groups through evolutionary development) include the presence in the plants of

oligosaccharide An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/; from the Greek ὀλίγος ''olígos'', "a few", and σάκχαρ ''sácchar'', "sugar") is a saccharide polymer containing a small number (typically two to ten) of monosaccharides (simple sugar ...

inulin Inulins are a group of naturally occurring polysaccharides produced by many types of plants, industrially most often extracted from chicory. The inulins belong to a class of dietary fibers known as fructans. Inulin is used by some plants as a mea ...

, a nutrient storage molecule used instead of

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

; and unique

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

morphology. The stamens are usually found around the

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

, either aggregated densely or fused into a tube, probably an

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...

in association with the plunger (brush; or secondary)

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...

that is common among the families of the order, wherein pollen is collected and stored on the length of the pistil.

Taxonomy

The name and order Asterales is botanically venerable, dating back to at least 1926 in the Hutchinson system of plant taxonomy when it contained only five families, of which only two are retained in the

APG III APG is an abbreviation with several different meanings: * Aberdeen Proving Ground, a United States Army installation in Aberdeen, Maryland, also ** Phillips Army Airfield, the airfield of the above, from its IATA airport code * Aboriginal Provisiona ...

classification. Under the

Cronquist system The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) a ...

of taxonomic classification of flowering plants,

was the only family in the group, but newer systems (such as

APG II The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Gr ...

and APG III) have expanded it to 11. In the classification system of

Rolf Dahlgren Rolf Martin Theodor Dahlgren (7 July 1932 – 14 February 1987) was a Swedish- Danish botanist and professor at the University of Copenhagen from 1973 to his death. Life Dahlgren was born in Örebro on 7 July 1932 to apothecary Rudolf Dahlgren ...

the Asterales were in the superorder Asteriflorae (also called Asteranae). The order Asterales currently includes 11 families, the largest of which are the Asteraceae, with about 25,000 species, and the

Campanulaceae The family Campanulaceae (also bellflower family), of the order Asterales, contains nearly 2400 species in 84 genera of herbaceous plants, shrubs, and rarely small trees, often with milky sap. Among them are several familiar garden plants belo ...

(bellflowers), with about 2,000 species. The remaining families count together for less than 1500 species. The two large families are cosmopolitan, with many of their species found in the Northern Hemisphere, and the smaller families are usually confined to Australia and the adjacent areas, or sometimes South America. Only the Asteraceae have composite flower heads; the other families do not, but share other characteristics such as storage of inulin that define the 11 families as more closely related to each other than to other plant families or orders such as the

. The phylogenetic tree according to APG III for the Campanulid clade is as below.

Phylogeny

Although most extant species of Asteraceae are herbaceous, the examination of the basal members in the family suggests that the common ancestor of the family was an arborescent plant, a tree or shrub, perhaps adapted to dry conditions, radiating from South America. Less can be said about the Asterales themselves with certainty, although since several families in Asterales contain trees, the ancestral member is most likely to have been a tree or shrub. Because all clades are represented in the Southern Hemisphere but many not in the Northern Hemisphere, it is natural to conjecture that there is a common southern origin to them. Asterales are

angiosperms 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 ...

, flowering plants that appeared about 140 million years ago. The Asterales order probably originated in the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

(145 – 66 Mya) on the supercontinent

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

which broke up from 184 – 80 Mya, forming the area that is now Australia, South America, Africa, India and Antarctica. Asterales contain about 14% of eudicot diversity. From an analysis of relationships and diversities within the Asterales and with their superorders, estimates of the age of the beginning of the Asterales have been made, which range from 116 Mya to 82Mya. However few fossils have been found, of the

Menyanthaceae Menyanthaceae is a family of aquatic and wetland plants in the order Asterales. There are approximately 60-70 species in six genera distributed worldwide. The simple or compound leaves arise alternately from a creeping rhizome. In the submers ...

-Asteraceae clade in the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

, about 29 Mya. Fossil evidence of the Asterales is rare and belongs to rather recent epochs, so the precise estimation of the order's age is quite difficult. An Oligocene (34 – 23 Mya) pollen is known for Asteraceae and

Goodeniaceae Goodeniaceae is a family (biology), family of flowering plants in the Order (biology), order Asterales. It contains about 404 species in twelve genera. The family is distributed mostly in Australia, except for the genus ''Scaevola (plant), Scaevo ...

, and seeds from Oligocene and

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

(23 – 5.3 Mya) are known for Menyanthaceae and Campanulaceae respectively.

Biogeography

The core Asterales are

Stylidiaceae The family Stylidiaceae is a taxon of dicotyledonous flowering plants. It consists of five genera with over 240 species, most of which are endemic to Australia and New Zealand. Members of Stylidiaceae are typically grass-like herbs or small shrub ...

(six

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

), APA

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

(

Alseuosmiaceae Alseuosmiaceae is a plant family of the order Asterales found in Australia, New Caledonia, and New Zealand. They are shrubs with leaves arranged in spirals or whorls about the stem. The flowers are solitary or borne in raceme or fascicle inflor ...

Phellinaceae ''Phelline'' is a genus of shrubs and the sole member of the family Phellinaceae, a family of flowering plants endemic to New Caledonia. It is placed in the order Asterales and is related to two other small plant families: Alseuosmiaceae and Arg ...

and

Argophyllaceae Argophyllaceae is a family of shrubs or small trees belonging to the order Asterales. The family includes c. 24 species in two genera, '' Argophyllum'' and ''Corokia''. Members of the family are native to eastern Australia, New Zealand, Lord How ...

, together seven genera), MGCA clade (Menyanthaceae, Goodeniaceae,

Calyceraceae Calyceraceae is a plant family in the order Asterales. The natural distribution of the about sixty species belonging to this family is restricted to the southern half of South America. The species of the family resemble both the family Asteraceae ...

, in total twenty genera), and Asteraceae (about sixteen hundred genera). Other Asterales are

Rousseaceae Rousseaceae is a plant family in the order Asterales containing trees and shrubs. The fruit is a berry or capsule. Leaves are simple, with toothed margins. Leaf stipules are not seen in this group. The family contains four genera and twelve or t ...

(four genera), Campanulaceae (eighty-four genera) and

Pentaphragmataceae ''Pentaphragma'' is a genus of flowering plants. ''Pentaphragma'' is the sole genus in Pentaphragmataceae, a family in the order Asterales. These species are fleshy herbs, with asymmetrical leaf blades. They are found in Southeast Asia. ''Pentaph ...

(one genus). All Asterales families are represented in the Southern Hemisphere; however, Asteraceae and Campanulaceae are cosmopolitan and Menyanthaceae nearly so.

Uses

The Asterales, by dint of being a super-set of the family Asteraceae, include some species grown for food, including the

sunflower The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), as ...

('' Helianthus annuus''),

lettuce Lettuce (''Lactuca sativa'') is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, ...

(''Lactuca sativa'') and

chicory Common chicory ('' Cichorium intybus'') is a somewhat woody, perennial herbaceous plant of the family Asteraceae, usually with bright blue flowers, rarely white or pink. Native to the Old World, it has been introduced to North America and Austra ...

('' Cichorium''). Many are also used as spices and traditional medicines. Asterales are common plants and have many known uses. For example,

pyrethrum ''Pyrethrum'' was a genus of several Old World plants now classified as ''Chrysanthemum'' or ''Tanacetum'' which are cultivated as ornamentals for their showy flower heads. Pyrethrum continues to be used as a common name for plants formerly inclu ...

(derived from Old World members of the genus ''

Chrysanthemum Chrysanthemums (), sometimes called mums or chrysanths, are flowering plants of the genus ''Chrysanthemum'' in the family Asteraceae. They are native to East Asia and northeastern Europe. Most species originate from East Asia and the center ...

'') is a natural insecticide with minimal environmental impact. Wormwood, derived from a genus that includes the

sagebrush Sagebrush is the common name of several woody and herbaceous species of plants in the genus ''Artemisia''. The best known sagebrush is the shrub ''Artemisia tridentata''. Sagebrushes are native to the North American west. Following is an alph ...

, is used as a source of flavoring for absinthe, a bitter classical liquor of European origin.

References

External links