Poales

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Poales
Temporal range: Late Cretaceous - Recent (but see text) 66–0  Ma
Zboze.jpg
Common wheat (Triticum aestivum)
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Small [1]
Families

See text

Diversity
About 1,050 genera[ citation needed ]

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.

Contents

Description

Billbergia pyramidalis of family Bromeliaceae Billbergia pyramidalis in Hyderabad Nursery W IMG 0425.jpg
Billbergia pyramidalis of family Bromeliaceae

The flowers are typically small, enclosed by bracts, and arranged in inflorescences (except in three species of the genus Mayaca , which possess very reduced, one-flowered inflorescences). The flowers of many species are wind pollinated; the seeds usually contain starch.

Taxonomy

The APG III system (2009) accepts the order within a monocot clade called commelinids, and accepts the following 16 families: [1]

The earlier APG system (1998) adopted the same placement of the order, although it used the spelling "commelinoids". It did not include the Bromeliaceae and Mayaceae, but had the additional families Prioniaceae (now included in Thurniaceae), Sparganiaceae (now in Typhaceae), and Hydatellaceae (now transferred out of the monocots; recently discovered to be an 'early-diverging' lineage of flowering plants).

The morphology-based Cronquist system did not include an order named Poales, assigning these families to the orders Bromeliales, Cyperales, Hydatellales, Juncales, Restionales and Typhales.

In early systems, an order including the grass family did not go by the name Poales but by a descriptive botanical name such as Graminales in the Engler system (update of 1964) and in the Hutchinson system (first edition, first volume, 1926), Glumiflorae in the Wettstein system (last revised 1935) or Glumaceae in the Bentham & Hooker system (third volume, 1883).

Evolution and phylogeny

The earliest fossils attributed to the Poales date to the late Cretaceous period about 66 million years ago, though some studies (e.g., Bremer, 2002) suggest the origin of the group may extend to nearly 115 million years ago, likely in South America. The earliest known fossils include pollen and fruits.

The phylogenetic position of Poales within the commelinids was difficult to resolve, but an analysis using complete chloroplast DNA found support for Poales as sister group of Commelinales plus Zingiberales. [2] Major lineages within the Poales have been referred to as bromeliad, cyperid, xyrid, graminid, and restiid clades. A phylogenetic analysis resolved most relationships within the order but found weak support for the monophyly of the cyperid clade. [3] The relationship between Centrolepidaceae and Restoniaceae within the restiid clade remains unclear; the first may actually be embedded in the latter. [3] [4]

Poales

Diversity

The four most species-rich families in the order are:[ citation needed ]

Historic taxonomy

Cyperales

Cyperus javanicus Cyperus javanicus closeup.jpg
Cyperus javanicus

Cyperales was a name for an order of flowering plants. As used in the Engler system (update, of 1964) and in the Wettstein system it consisted of only the single family. In the Cronquist system it is used for an order (placed in subclass Commelinidae ) and circumscribed as (1981): [5]

The APG system now assigns the plants involved to the order Poales.

Eriocaulales

Eriocaulon decangulare Eriocaulon decangulare (1832).jpg
Eriocaulon decangulare

Eriocaulales is a botanical name for an order of flowering plants. The name was published by Takenoshin Nakai. In the Cronquist system the name was used for an order placed in the subclass Commelinidae . The order consisted of one family only (1981):

The APG IV system now assigns these plants to the order Poales.

Uses

The Poales are the most economically important order of monocots and possibly the most important order of plants in general. Within the order, by far the most important family economically is the family of grasses (Poaceae, syn. Gramineae), which includes the starch staples barley, maize, millet, rice, and wheat as well as bamboos (mostly used structurally, like wood, but somewhat as vegetables), and a few "seasonings" like sugarcane and lemongrass. Graminoids, especially the grasses, are typically dominant in open (low moisture but not yet arid, or also fire climax) habitats like prairie/steppe and savannah and thus form a large proportion of the forage of grazing livestock. Possibly due to pastoral nostalgia or simply a desire for open areas for play, they dominate most Western yards as lawns, which consume vast sums of money in upkeep (artificial grazing—mowing—for aesthetics and to keep the allergenic flowers suppressed, irrigation, and fertilizer). Many Bromeliaceae are used as ornamental plants (and one, the pineapple, is internationally grown in the tropics for fruit). Many wetland species of sedges, rushes, grasses, and cattails are important habitat plants for waterfowl, are used in weaving chair seats, and (especially cattails) were important pre-agricultural food sources for man. Two sedges, chufa ( Cyperus esculentus , also a significant weed) and water chestnut ( Eleocharis dulcis ) are still at least locally important wetland starchy root crops.

Related Research Articles

<span class="mw-page-title-main">Arecales</span> Order of flowering plants

Arecales is an order of flowering plants. The order has been widely recognised only for the past few decades; until then, the accepted name for the order including these plants was Principes.

<span class="mw-page-title-main">Restionales</span> Order of plants

Restionales is an order of flowering plants. In the Cronquist system it is used for an order and circumscribed as:

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:

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).

<span class="mw-page-title-main">Restionaceae</span> Family of flowering plants

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.

<span class="mw-page-title-main">Typhaceae</span> Family of flowering plants

The Typhaceae are a family of flowering plants, sometimes called the cattail family. The botanical name for the family has been recognized by most taxonomists.

<span class="mw-page-title-main">Xyridaceae</span> Family of flowering plants

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.

<span class="mw-page-title-main">Sparganiaceae</span> Family of plants

Sparganiaceae is a family of flowering plants. Such a family was previously recognized by most taxonomists.

<span class="mw-page-title-main">Thurniaceae</span> Family of flowering plants

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 system of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved APG II in 2003, APG III system in 2009 and APG IV system in 2016.

<span class="mw-page-title-main">Commelinids</span> 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.

<span class="mw-page-title-main">Rapateaceae</span> Family of flowering plants

The Rapateaceae are a family of flowering plants. The botanical name has been recognized by most taxonomists.

The Kubitzki system is a system of plant taxonomy devised by Klaus Kubitzki, and is the product of an ongoing survey of vascular plants, entitled The Families and Genera of Vascular Plants, and extending to 15 volumes in 2018. The survey, in the form of an encyclopedia, is important as a comprehensive, multivolume treatment of the vascular plants, with keys to and descriptions of all families and genera, mostly by specialists in those groups. The Kubitzki system served as the basis for classification in Mabberley's Plant-Book, a dictionary of the vascular plants. Mabberley states, in his Introduction on page xi of the 2008 edition, that the Kubitzki system "has remained the standard to which other literature is compared".

<span class="mw-page-title-main">Hydatellaceae</span> Family of flowering plants

Hydatellaceae are a family of small, aquatic flowering plants. The family consists of tiny, relatively simple plants occurring in Australasia and India. It was formerly considered to be related to the grasses and sedges, but has been reassigned to the order Nymphaeales as a result of DNA and morphological analyses showing that it represents one of the earliest groups to split off in flowering-plant phylogeny, rather than having a close relationship to monocots, which it bears a superficial resemblance to due to convergent evolution. The family includes only the genus Trithuria, which has at least 13 species, although species diversity in the family has probably been substantially underestimated.

<span class="mw-page-title-main">Anarthriaceae</span> Family of flowering plants

The Anarthriaceae was a family of three genera, Anarthria, Hopkinsia and Lyginia of flowering plants, now included in Restionaceae following APG IV (2016). The family is accepted in the Angiosperm Phylogeny Group's classification system, APG III system, but is not considered a separate family in many other taxonomic systems. The three genera are herbaceous but differ greatly in characteristics.

<span class="mw-page-title-main">Centrolepidaceae</span> Family of flowering plants

Centrolepidaceae was a family of flowering plants now included in Restionaceae following APG IV (2016). The botanical name has been recognized by most taxonomists.

<span class="mw-page-title-main">Ecdeiocoleaceae</span> Family of grasses

The Ecdeiocoleaceae comprise a family of flowering plants with two genera and three species. The botanical name has rarely been recognized by taxonomists.

<span class="mw-page-title-main">Joinvilleaceae</span> Family of flowering plants

The Joinvilleaceae are a family of flowering plants with a single genus including four species. The APG II system, of 2003 assigns it to the order Poales in the clade commelinids in the monocots. The family consists of one genus with four currently accepted species, distributed from the Malay Peninsula to the Caroline Islands and high islands in the Pacific Ocean. It is evolutionarily significant as a relictual group closely related to grasses. They closely resemble large grass plants, in both general appearance and microanatomy, but possess fleshy fruits.

The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a further revision, the APG IV system.

References

  1. 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 . hdl: 10654/18083 .
  2. Barrett, Craig F.; Baker, William J.; Comer, Jason R.; Conran, John G.; Lahmeyer, Sean C.; Leebens-Mack, James H.; Li, Jeff; Lim, Gwynne S.; Mayfield-Jones, Dustin R.; Perez, Leticia; Medina, Jesus; Pires, J. Chris; Santos, Cristian; Wm. Stevenson, Dennis; Zomlefer, Wendy B.; Davis, Jerrold I. (2015). "Plastid genomes reveal support for deep phylogenetic relationships and extensive rate variation among palms and other commelinid monocots". New Phytologist. 209 (2): 855–870. doi: 10.1111/nph.13617 . ISSN   0028-646X. PMID   26350789.
  3. 1 2 Bouchenak-Khelladi, Yanis; Muasya, A. Muthama; Linder, H. Peter (2014). "A revised evolutionary history of Poales: origins and diversification". Botanical Journal of the Linnean Society. 175 (1): 4–16. doi: 10.1111/boj.12160 . ISSN   0024-4074. Open Access logo PLoS transparent.svg
  4. Briggs, Barbara G.; Marchant, Adam D.; Perkins, Andrew J. (2014). "Phylogeny of the restiid clade (Poales) and implications for the classification of Anarthriaceae, Centrolepidaceae and Australian Restionaceae". Taxon. 63 (1): 24–46. doi:10.12705/631.1. ISSN   0040-0262.
  5. D.J. Mabberley. 2000. The Plant-Book, 2nd ed. Cambridge University Press, Cambridge, UK, 858 p. [H. Pfefferkorn/H. Pfefferkorn/H. Pfefferkorn]

Bibliography