Commelinids Temporal range: | |
---|---|
Cock's-foot grass ( Dactylis glomerata ) | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Clade: | Commelinids |
Orders | |
Diversity [ citation needed ] | |
About 1,420 genera |
In plant taxonomy, commelinids (originally commelinoids [1] [2] ) is a clade of flowering plants within the monocots, distinguished by having cell walls containing ferulic acid. [3] [4] Well-known commelinids include palms and relatives (order Arecales), dayflowers, spiderworts, kangaroo paws, and water hyacinth (order Commelinales), grasses, bromeliads, rushes, and sedges (order Poales), and ginger, cardamom, turmeric, galangal, bananas, plantains, and bird of paradise flower (order Zingiberales).
The commelinids are the only clade that the APG IV system has informally named within the monocots. The remaining monocots are a paraphyletic unit. Also known as the commelinid monocots it forms one of three groupings within the monocots, and the final branch; the other two groups are the alismatid monocots and the lilioid monocots.
Members of the commelinid clade have cell walls containing UV-fluorescent ferulic acid. [3] [4]
The commelinids constitute a well-supported clade within the monocots, [5] and this clade has been recognized in all four APG classification systems. It consists of four orders:
Phylogenetic tree showing position of the commelinids within the monocots [6]
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As of APG IV (2016) the family Dasypogonaceae is no longer directly placed under commelinids but instead a family of order Arecales. [6]
The commelinids were first recognized as a formal group in 1967 by Armen Takhtajan, who named them the Commelinidae and assigned them to a subclass of Liliopsida (monocots). [7] The name was also used in the 1981 Cronquist system. However, by the release of his 1980 system of classification, Takhtajan had merged this subclass into a larger one, and no longer considered it to be a clade.[ citation needed ]
The Takhtajan system treated this as one of six subclasses within the class Liliopsida (=monocotyledons). It consisted of the following:[ citation needed ]
subclass Commelinidae
superorder Bromelianae
order Bromeliales
order Velloziales
superorder Pontederianae
order Philydrales
order Pontederiales
order Haemodorales
superorder Zingiberanae
order Musales
order Lowiales
order Zingiberales
order Cannales
superorder Commelinanae
order Commelinales
order Mayacales
order Xyridales
order Rapateales
order Eriocaulales
superorder Hydatellanae
order Hydatellales
superorder Juncanae
order Juncales
order Cyperales
superorder Poanae
order Flagellariales
order Restionales
order Centrolepidales
order Poales
The Cronquist system treated this as one of four subclasses within the class Liliopsida. It consisted of the following:[ citation needed ]
subclass Commelinidae
order Commelinales
order Eriocaulales
order Restionales
order Juncales
order Cyperales
order Hydatellales
order Typhales
The APG II system does not use formal botanical names above the rank of order; most of the members were assigned to the clade commelinids in the monocots (its predecessor, the APG system used the clade commelinoids). [8] [9]
The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food crop in the order is the taro plant, Colocasia esculenta.
Arecales is an order of flowering plants. The order has been widely named as such only for the past few decades; until then, the accepted name for the order including these plants was Principes. The order includes palms and relatives.
Commelinales is an order of flowering plants. It comprises five families: Commelinaceae, Haemodoraceae, Hanguanaceae, Philydraceae, and Pontederiaceae. All the families combined contain over 885 species in about 70 genera; the majority of species are in the Commelinaceae. Plants in the order share a number of synapomorphies that tie them together, such as a lack of mycorrhizal associations and tapetal raphides. Estimates differ as to when the Commelinales evolved, but most suggest an origin and diversification sometime during the mid- to late Cretaceous. Depending on the methods used, studies suggest a range of origin between 123 and 73 million years, with diversification occurring within the group 110 to 66 million years ago. The order's closest relatives are in the Zingiberales, which includes ginger, bananas, cardamom, and others.
The Dioscoreales are an order of monocotyledonous flowering plants, organized under modern classification systems, such as the Angiosperm Phylogeny Group or the Angiosperm Phylogeny Web. Among monocot plants, Dioscoreales are grouped with the lilioid monocots, wherein they are a sister group to the Pandanales. In total, the order Dioscoreales comprises three families, 22 genera and about 850 species.
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 Poales are a large order of flowering plants in the monocotyledons, and includes families of plants such as the grasses, bromeliads, rushes and sedges. Sixteen plant families are currently recognized by botanists to be part of Poales.
The Zingiberales are flowering plants forming one of four orders in the commelinids clade of monocots, together with its sister order, Commelinales. The order includes 68 genera and 2,600 species. Zingiberales are a unique though morphologically diverse order that has been widely recognised as such over a long period of time. They are usually large herbaceous plants with rhizomatous root systems and lacking an aerial stem except when flowering. Flowers are usually large and showy, and the stamens are often modified (staminodes) to also form colourful petal-like structures that attract pollinators.
Hydatellales is a botanical name for an order of flowering plants. In the Cronquist system, 1981, the name was used for an order placed in the subclass Commelinidae in class Liliopsida [=monocotyledons]. The order consisted of one family only:
Monocotyledons, commonly referred to as monocots, are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided; the rest of the flowering plants have two cotyledons and were classified as dicotyledons, or dicots.
Magnoliopsida is a valid botanical name for a class of flowering plants. By definition the class will include the family Magnoliaceae, but its circumscription can otherwise vary, being more inclusive or less inclusive depending upon the classification system being discussed.
LiliopsidaBatsch is a botanical name for the class containing the family Liliaceae. It is considered synonymous with the name monocotyledon. Publication of the name is credited to Scopoli : see author citation (botany). This name is formed by replacing the termination -aceae in the name Liliaceae by the termination -opsida.
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 and An Integrated System of Classification of Flowering Plants (1981).
The Restionaceae, also called restiads and restios, are a family of flowering plants native to the Southern Hemisphere; they vary from a few centimeters to 3 meters in height. Following the APG IV (2016): the family now includes the former families Anarthriaceae, Centrolepidaceae and Lyginiaceae, and as such includes 51 genera with 572 known species. Based on evidence from fossil pollen, the Restionaceae likely originated more than 65 million years ago during the Late Cretaceous period, when the southern continents were still part of Gondwana.
The Xyridaceae are a family of flowering plants. This family has been recognized by many taxonomists and is known as the yellow-eyed grass family.
The Thurniaceae are a family of flowering plants composed of two genera with four species. The botanical name has been recognized by most taxonomists.
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.
A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950s onwards. It is usually compared to the Cronquist system. It admits paraphyletic groups.
The Rapateaceae are a family of flowering plants. The botanical name has been recognized by most taxonomists.
Arecidae is a botanical name at the rank of subclass. Circumscription of the subclass will vary with the taxonomic system being used ; the only requirement being that it includes the family Arecaceae.
Scitamineae is a descriptive botanical name. Historically it has been applied to a remarkably stable group of flowering plants, now referred to as Zingiberales: