Asterids

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Asterids
Potapsco fg13.jpg
Impatiens capensis (Ericales)
Origanum vulgare - harilik pune.jpg
Oregano from Lamiales
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Core eudicots
Clade: Superasterids
Clade: Asterids
Clades

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 plant with more than 80,000 species, about a third of the total flowering plant species [1] . [2] Well known plants in this clade include the common daisy, forget-me-nots, nightshades (including potatoes, eggplants, tomatoes, peppers and tobacco), the common sunflower, petunias, yacon, morning glory, sweet potato, coffee, lavender, lilac, olive, jasmine, honeysuckle, ash tree, teak, snapdragon, sesame, psyllium, garden sage, table herbs such as mint, basil, and rosemary, and rainforest trees such as Brazil nut.

Contents

Most of the taxa belonging to this clade had been referred to the Asteridae in the Cronquist system (1981) and to the Sympetalae in earlier systems.[ citation needed ] The name asterids (not necessarily capitalised) resembles the earlier botanical name but is intended to be the name of a clade rather than a formal ranked name, in the sense of the ICBN .

History

Genetic analysis carried out after APG II maintains that the sister to all other asterids are the Cornales. A second order that split from the base of the asterids are the Ericales. The remaining orders cluster into two clades, the lamiids and the campanulids. The structure of both of these clades has changed in APG III. [3] [4]

In the APG III system, the following clades were renamed:

euasterids I → lamiids
euasterids II → campanulids [3] [4]

Phylogeny

The phylogenetic tree presented hereinafter has been proposed by the APG IV project. [2]

asterids 

  Cornales

  Ericales

euasterids
campanulids

Aquifoliales

Asterales

Escalloniales

Bruniales

Apiales

Dipsacales

Paracryphiales

lamiids

Icacinales

Metteniusales

Garryales

Boraginales

Gentianales

Vahliales

Lamiales

Solanales

Subdivision

lamiids

The lamiid subclade consists of about 40,000 species and account for about 15% of angiosperm diversity, characterized in general by superior ovaries and corollas with any fusion of the petals (sympetaly) occurring late in the process of development. The major part of lamiid diversity occurs in the group of five orders from Boraginales to Solanales, referred to informally as "core lamiids" (sometimes called Laminae), although Vahliales consists of the single small genus Vahlia. The remainder of the lamiids are referred to as "basal lamiids", in which Garryales is the sister group to the core lamiids. It has been suggested that the core lamiids radiated from an ancestral line of tropical trees in which the flowers were inconspicuous and the fruit large, drupaceous and often single-seeded. [5]

Related Research Articles

Apiales Order of eudicot flowering plants in the asterid group

The Apiales are an order of flowering plants. The families are those recognized in the APG III system. This is typical of the newer classifications, though there is some slight variation and in particular, the Torriceliaceae may be divided.

Malpighiales Eudicot order of flowering plants

The Malpighiales comprise one of the largest orders of flowering plants, containing about 36 families and more than 16,000 species, about 7.8% of the eudicots. The order is very diverse, containing plants as different as the willow, violet, poinsettia, manchineel, rafflesia and coca plant, and are hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems based only on plant morphology. Molecular clock calculations estimate the origin of stem group Malpighiales at around 100 million years ago (Mya) and the origin of crown group Malpighiales at about 90 Mya.

Solanales Order of dicot flowering plants

The Solanales are an order of flowering plants, included in the asterid group of dicotyledons. Some older sources used the name Polemoniales for this order.

Canellales Order of flowering plants

Canellales is the botanical name for an order of flowering plants, one of the four orders of the magnoliids. It is recognized by the most recent classification of flowering plants, the APG IV system. It is defined to contain two families: Canellaceae and Winteraceae, which comprise 136 species of fragrant trees and shrubs. The Canellaceae are found in tropical America and Africa, and the Winteraceae are part of the Antarctic flora. Although the order was defined based on phylogenetic studies, a number of possible synapomorphies have been suggested, relating to the pollen tube, the seeds, the thickness of the integument, and other aspects of the morphology.

Cornales Order of flowering plants

The Cornales are an order of flowering plants, early diverging among the asterids, containing about 600 species. Plants within the Cornales usually have four-parted flowers, drupaceous fruits, and inferior to half-inferior gynoecia topped with disc-shaped nectaries.

Angiosperm Phylogeny Group A collaborative research group for the classification of flowering plants

The Angiosperm Phylogeny Group, or APG, is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships discovered through phylogenetic studies.

Gelsemiaceae Family of plants

Gelsemiaceae is a family of flowering plants, belonging to the order Gentianales. The family contains only three genera: Gelsemium, Mostuea and Pteleocarpa. Gelsemium has three species, one native to Southeast Asia and southern China and two native to Central America, Mexico, and the southeastern United States. The eight species of Mostuea are native to tropical areas of South America, Africa, and Madagascar. The two genera were formerly classified in the family Loganiaceae. Pteleocarpa was originally placed in Boraginaceae or in its own family Pteleocarpaceae, but it is most closely related to Gelsemiaceae with which it shares significant characters.

Eudicots Clade of flowering plants

The eudicots, Eudicotidae or eudicotyledons are a clade of flowering plants mainly characterized by having two seed leaves upon germination. The term derives from Dicotyledons.

Peridiscaceae Family of flowering plants in the order Saxifragales

Peridiscaceae is a family of flowering plants in the order Saxifragales. Four genera comprise this family: Medusandra, Soyauxia, Peridiscus, and Whittonia., with a total of 12 known species. It has a disjunct distribution, with Peridiscus occurring in Venezuela and northern Brazil, Whittonia in Guyana, Medusandra in Cameroon, and Soyauxia in tropical West Africa. Whittonia is possibly extinct, being known from only one specimen collected below Kaieteur Falls in Guyana. In 2006, archeologists attempted to rediscover it, however, it proved unsuccessful.

The APG 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 Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009 by a further revision, the APG III system.

Commelinids A clade of monocot flowering plants

In plant taxonomy, commelinids is a clade of flowering plants within the monocots, distinguished by having cell walls containing ferulic acid.

Theophrastoideae Subfamily of flowering plant family Primulaceae

Theophrastoideae is a small subfamily of flowering plants in the family Primulaceae. It was formerly recognized as a separate family Theophrastaceae. As previously circumscribed, the family consisted of eight genera and 95 species of trees or shrubs, native to tropical regions of the Americas.

Escalloniaceae Family of flowering plants

Escalloniaceae is a family of flowering plants consisting of about 130 species in seven genera. In the APG II system it is one of eight families in the euasterids II clade (campanulids) that are unplaced as to order. More recent research has provided evidence that two of those families, Eremosynaceae and Tribelaceae, arose from within Escalloniaceae; the Angiosperm Phylogeny Website therefore merges these two families into Escalloniaceae, and also places the family alone in order Escalloniales.

Loasaceae Family of flowering plants

Loasaceae is a family of 15–20 genera and about 200–260 species of flowering plants in the order Cornales, native to the Americas and Africa. Members of the family include annual, biennial and perennial herbaceous plants, and a few shrubs and small trees. Members of the subfamily Loasoideae are known to exhibit rapid thigmonastic stamen movement when pollinators are present.

<i>Oncotheca</i> Genus of trees

Oncotheca is a genus of tree endemic to New Caledonia. There are two species, Oncotheca balansae and Oncotheca humboldtiana.

Bruniales Order of flowering plants

Bruniales is a valid botanic name at the rank of order. Until recently it was not in use, but a 2008 study suggested that Bruniaceae and Columelliaceae are sister clades. The latest revision of the APG system, APG III, places both families as the only members of the order Bruniales, which is sister to the Apiales, and one of the asterid taxa.

Tribeles australis, the sole species in the genus Tribeles, is a prostrate shrub native to Chile and Argentina.

Paracryphiaceae Family of shrubs

The Paracryphiaceae are a family of woody shrubs and trees native to Australia, southeast Asia, and New Caledonia. In the APG III system of 2009, the family is placed in its own order, Paracryphiales, in the campanulid clade of the asterids. In the earlier APG II system, the family was unplaced as to order and included only Paracryphia.

Mesangiospermae One of two clades of flowering plants

Mesangiospermae is a clade of flowering plants (angiosperms), informally called "mesangiosperms". They are one of two main groups of angiosperms. It is a name created under the rules of the PhyloCode system of phylogenetic nomenclature. There are about 350,000 species of mesangiosperms. The mesangiosperms contain about 99.95% of the flowering plants, assuming that there are about 175 species not in this group and about 350,000 that are. While such a clade with a similar circumscription exists in the APG III system, it was not given a name.

References

  1. Bremer, Kåre; Friis, elsemarie; Bremer, birgitta (1 June 2004). "Molecular Phylogenetic Dating of Asterid Flowering Plants Shows Early Cretaceous Diversification". Oxford University Press. 53 (3): 496–505. doi:10.1080/10635150490445913.
  2. 1 2 Angiosperm Phylogeny Group (2016). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV". Botanical Journal of the Linnean Society. 181 (1): 1–20. doi: 10.1111/boj.12385 .
  3. 1 2 Angiosperm Phylogeny Group (2003). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II". Botanical Journal of the Linnean Society. 141 (4): 399–436. doi: 10.1046/j.1095-8339.2003.t01-1-00158.x .
  4. 1 2 Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". Botanical Journal of the Linnean Society. 161 (2): 105–121. doi: 10.1111/j.1095-8339.2009.00996.x .
  5. Stull et al 2015.

Bibliography