Gentianales | |
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Gentiana cruciata | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Clade: | Lamiids |
Order: | Gentianales Juss. ex Bercht. & J.Presl |
Families | |
Synonyms | |
Gentianales is an order of flowering plant, included within the asterid clade of eudicots. It comprises more than 20,000 species in about 1,200 genera in 5 families. [1] More than 80% of the species in this order belong to the family Rubiaceae.
Many of these flowering plants are used in traditional medicine. [2] They have been used to treat pain, anxiety, cancers and neurological conditions.
According to molecular clock calculations, the lineage that led to Gentianales split from other plants about 108 million years ago [3] or 81 million years ago. [4]
In the classification system of Dahlgren the Gentiales were in the superorder Gentianiflorae (also called Gentiananae). The following families are included according to the APG III system: [5]
The following phylogenetic tree is based on molecular phylogenetic studies of DNA sequences. [6]
Gentianales | |
It takes its name from the family Gentianaceae, which in turn is based on the name of the type genus, Gentiana . The genus name is a tribute to Gentius, an Illyrian king.
This large order has a variety of different plants, ranging from small herbaceous plants and saprophytes to shrubs and large trees. [7] Species are, however, united by their simple and opposite leaves and typically have showy pentamerous flowers (flowers in which components occur in multiples of five) and show nuclear endosperm formation (in which cell division takes place without the cell wall forming between divisions). [1] [7] Many species have structures between the leaf petioles, such as ridges or stipules. [7] Many species also have colleters; thick hair-like structures that secrete mucilage, a thick gluey substance. [7]
Species of this order are found in moist climates around the world. They are most common in tropical regions. [7]
Many gentianales contain toxic compounds and species have a variety of uses. Some species are also grown ornamentally. [7] Well-known members of Gentianales are coffee, frangipani, Gardenia , gentian, oleander, and periwinkle.
Certain species belonging to the order Gentianales have been used in traditional medicine in rural southeastern Asia countries. Gelsemium sempervirens has been used in North American folk medicine to treat conditions such as anxiety, migraines/headaches, and neuralgia, while Gelsemium elegans has been used in China to treat rheumatoid arthritis pain, neuropathic pain, skin ulcers, and even cancers. [2]
The compounds found in some species are used in the synthesis of modern medicines. Cinchona trees, for example, are a source of quinine, which is used to treat malaria. [8] Vinblastine, which has anti-tumor properties as it disrupts cell division, is used in chemotherapy. It is extracted from the Madagascar periwinkle.
Asterales is an order of dicotyledonous flowering plants that includes the large family Asteraceae known for composite flowers made of florets, and ten families related to the Asteraceae. While asterids in general are characterized by fused petals, composite flowers consisting of many florets create the false appearance of separate petals.
The Ericales are a large and diverse order of dicotyledons. Species in this order have considerable commercial importance including for tea, persimmon, blueberry, kiwifruit, Brazil nuts, argan, and azalea. The order includes trees, bushes, lianas, and herbaceous plants. Together with ordinary autophytic plants, the Ericales include chlorophyll-deficient mycoheterotrophic plants and carnivorous plants.
Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) places this order in the monocot clade. In APG III, the family Luzuriagaceae is combined with the family Alstroemeriaceae and the family Petermanniaceae is recognized. Both the order Lililiales and the family Liliaceae have had a widely disputed history, with the circumscription varying greatly from one taxonomist to another. Previous members of this order, which at one stage included most monocots with conspicuous tepals and lacking starch in the endosperm are now distributed over three orders, Liliales, Dioscoreales and Asparagales, using predominantly molecular phylogenetics. The newly delimited Liliales is monophyletic, with ten families. Well known plants from the order include Lilium (lily), tulip, the North American wildflower Trillium, and greenbrier.
The order Lamiales are an order in the asterid group of dicotyledonous flowering plants. It includes about 23,810 species, 1,059 genera, and is divided into about 25 families. These families include Acanthaceae, Bignoniaceae, Byblidaceae, Calceolariaceae, Carlemanniaceae, Gesneriaceae, Lamiaceae, Lentibulariaceae, Linderniaceae, Martyniaceae, Mazaceae, Oleaceae, Orobanchaceae, Paulowniaceae, Pedaliaceae, Peltantheraceae, Phrymaceae, Plantaginaceae, Plocospermataceae, Schlegeliaceae, Scrophulariaceae, Stilbaceae, Tetrachondraceae, Thomandersiaceae, Verbenaceae.
Rosales is an order of flowering plants. It is sister to a clade consisting of Fagales and Cucurbitales. It contains about 7,700 species, distributed into about 260 genera. Rosales comprise nine families, the type family being the rose family, Rosaceae. The largest of these families are Rosaceae (91/4828) and Urticaceae (53/2625). The order Rosales is divided into three clades that have never been assigned a taxonomic rank. The basal clade consists of the family Rosaceae; another clade consists of four families, including Rhamnaceae; and the third clade consists of the four urticalean families.
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.
Rubiaceae is a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules and sympetalous actinomorphic flowers. The family contains about 14,100 species in about 580 genera, which makes it the fourth-largest angiosperm family. Rubiaceae has a cosmopolitan distribution; however, the largest species diversity is concentrated in the tropics and subtropics. Economically important genera include Coffea, the source of coffee; Cinchona, the source of the antimalarial alkaloid quinine; ornamental cultivars ; and historically some dye plants.
Gentianaceae is a family of flowering plants of 105 genera and about 1600 species.
The Loganiaceae are a family of flowering plants classified in order Gentianales. The family includes up to 13 genera, distributed around the world's tropics. There are not any great morphological characteristics to distinguish these taxa from others in the order Gentianales.
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.
In the APG IV system (2016) for the classification of flowering plants, the name asterids denotes a clade. Asterids is the largest group of flowering plants, with more than 80,000 species, about a third of the total flowering plant species. Well-known plants in this clade include the common daisy, forget-me-nots, nightshades, the common sunflower, petunias, yacon, morning glory, lettuce, sweet potato, coffee, lavender, lilac, olive, jasmine, honeysuckle, ash tree, teak, snapdragon, sesame, psyllium, garden sage, blueberries, table herbs such as mint, basil, and rosemary, and rainforest trees such as Brazil nut.
Sympetally is a flower characteristic that historically was used to classify a grouping of plants termed Sympetalae, but this term has been abandoned in newer molecular based classifications, although the grouping has similarity to the modern term asterids.
Boraginales is an order of flowering plants in the asterid clade, with a total of about 125 genera and 2,700 species. Different taxonomic treatments either include only a single family, the Boraginaceae, or divide it into up to eleven families. Its herbs, shrubs, trees and lianas (vines) have a worldwide distribution.
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.
Pteleocarpa is a genus of flowering plants. The only member of the genus is the western Malesian tree Pteleocarpa lamponga. It has had a varied systematic history and has been placed in the families Icacinaceae, Cardiopteridaceae, Boraginaceae, and others. It has long been regarded as enigmatic. For example, its winged fruit is quite odd within the family Boraginaceae, where it was usually placed in the 2000s. The family name Pteleocarpaceae had been used, but was not validly published until 2011, when the required description was published in Kew Bulletin. A morphological study of Pteleocarpa was published in 2014. Also in 2014, a molecular phylogenetic study of the lamiids sampled Pteleocarpa and resolved it as sister to Gelsemiaceae. Both genera of Gelsemiaceae were sampled and this result had maximum statistical support in three different methods of cladistic analysis. The authors of that study recommended that Pteleocarpa be included in Gelsemiaceae. This was formally done in 2014 by altering the description of the family to accommodate it. In the APG IV system published in 2016, Pteleocarpa is included in Gelsemiaceae.
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.
In phylogenetic nomenclature, the Pentapetalae are a large group of eudicots that were informally referred to as the "core eudicots" in some papers on angiosperm phylogenetics. They comprise an extremely large and diverse group accounting for about 65% of the species richness of the angiosperms, with wide variability in habit, morphology, chemistry, geographic distribution, and other attributes. Classical systematics, based solely on morphological information, was not able to recognize this group. In fact, the circumscription of the Pentapetalae as a clade is based on strong evidence obtained from DNA molecular analysis data.
Birgitta Bremer, Swedish botanist and academic, is professor at Stockholm University, and director of the Bergius Botanic Garden.
Contortae as a term has appeared in several senses in botanical taxonomy, most conspicuously as follows: