Poales
Encyclopedia
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s in the monocotyledon
Monocotyledon
Monocotyledons, also known as monocots, are one of two major groups of flowering plants that are traditionally recognized, the other being dicotyledons, or dicots. Monocot seedlings typically have one cotyledon , in contrast to the two cotyledons typical of dicots...
s, and includes families of plants such as the grasses
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
, bromeliads, and sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
s. Sixteen plant families are currently recognized by botanists to be part of Poales.
Recent studies (e.g., Bremer, 2000) place the origin of the Poales in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
nearly 115 million years ago. The earliest known fossils include pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
and fruits that have been dated to the late Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are typically small, enclosed by bracts, and arranged in an inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
(except in the genus Mayaca, with solitary terminal flowers). The flowers of many species are wind pollinated; the seeds usually contain starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
.
The APG III system
APG III system
The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...
(2009) accepts the order and places it in a clade called commelinids
Commelinids
In plant taxonomy, commelinids is a name used by the APG III system for a clade within the monocots, which in its turn is a clade within the angiosperms. The commelinids are the only clade that the APG has informally named within the monocots...
, in the monocots. It uses this circumscription:
- order Poales
- family AnarthriaceaeAnarthriaceaeAnarthriaceae is the botanical name for a family of flowering plants. Such a family has rarely been recognized by taxonomists.The APG II system, of 2003 , does recognize this family, and assigns it to the order Poales in the clade commelinids, in the monocots...
- family BromeliaceaeBromeliaceaeBromeliaceae is a family of monocot flowering plants of around 3,170 species native mainly to the tropical Americas, with a few species found in the American subtropics and one in tropical west Africa, Pitcairnia feliciana...
- family CentrolepidaceaeCentrolepidaceaeCentrolepidaceae is a botanical name for a family of flowering plants. Such a family has been recognized by most taxonomists.The APG II system, of 2003 , also recognises such a family, and assigns it to the order Poales in the clade commelinids in the monocots.The family is now regarded as...
- family CyperaceaeCyperaceaeCyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
- family EcdeiocoleaceaeEcdeiocoleaceaeEcdeiocoleaceae is the botanical name for a family of flowering plants. Such a family has rarely been recognized by taxonomists.The APG II system, in 2003 , does recognize such a family, and assigns it to the order Poales in the clade commelinids, in the monocots...
- family EriocaulaceaeEriocaulaceaeThe Eriocaulaceae or pipewort family is a family of monocotyledonous flowering plants in the order Poales. The family is large, with about 1,150-1,200 species described in ten genera. The family is widely distributed, with the centers of diversity for the group occurring in tropical regions,...
- family FlagellariaceaeFlagellariaceaeFlagellariaceae is the botanical name for a family of flowering plants. Such a family has rarely been recognized by taxonomists.The APG II system, of 2003 , does recognize such a family, and assigns it to the order Poales in the clade commelinids, in the monocots...
- family JoinvilleaceaeJoinvilleaceaeJoinvilleaceae is a family of flowering plants. 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...
- family JuncaceaeJuncaceaeJuncaceae, the rush family, are a monocotyledonous family of flowering plants. There are eight genera and about 400 species. Members of the Juncaceae are slow-growing, rhizomatous, herbaceous plants, and they may superficially resemble grasses. They often grow on infertile soils in a wide range...
- family MayacaceaeMayacaceaeMayaca is a genus of flowering plants, often placed in its own family, the Mayacaceae. In the APG II system of 2003, it is assigned to the Order Poales in the clade commelinids. The Cronquist system, of 1981, also recognised such a family and placed it in the order Commelinales in the subclass...
- family PoaceaePoaceaeThe Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
- family RapateaceaeRapateaceaeRapateaceae is the botanical name for a family of flowering plants. Such a family has been recognized by most taxonomists.The APG II system, of 2003 also recognizes this family, and assigns it to the order Poales in the clade commelinids, in the monocots...
- family RestionaceaeRestionaceaeRestionaceae, also called restiads, is the botanical name for a family of rush-like flowering plants native to the Southern Hemisphere.- Description :...
- family ThurniaceaeThurniaceaeThurniaceae is the botanical name for a family of flowering plants. Such a family has been recognized by most taxonomists.The APG II system, of 2003, also recognizes such a family, and assigns it to the order Poales in the clade commelinids, in the monocots...
- family TyphaceaeTyphaceaeTyphaceae is the botanical name for a family of flowering plants. Such a family has been recognized by most taxonomists.The APG II system, of 2003 , also recognizes this family, and assigns it to the order Poales in the clade commelinids, in the monocots...
- family XyridaceaeXyridaceaeXyridaceae is the botanical name of a family of flowering plants. Such a family has been recognized by many taxonomists and is known as the Yellow-eyed-grass Family....
- family Anarthriaceae
The earlier APG system
APG system
The APG system of plant classification is the first, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in 1998 by the Angiosperm Phylogeny Group. It was superseded in 2003 by a revision, the APG II system, and then in 2009 by a further...
(1998) adopted the same placement, although it used the spelling "commelinoids", and used the following circumscription (i.e., it did not include the plants in families Bromeliaceae and Mayacaceae in the order):
- order Poales
- family Anarthriaceae
- family Centrolepidaceae
- family Cyperaceae
- family Ecdeiocoleaceae
- family Eriocaulaceae
- family Flagellariaceae
- family Hydatellaceae (now transferred out of the monocots; recently discovered to be an 'early-diverging' lineage of flowering plants.)
- family Joinvilleaceae
- family Juncaceae
- family Poaceae
- family Prioniaceae
- family Restionaceae
- family Sparganiaceae (now included in family Typhaceae.)
- family Thurniaceae
- family Typhaceae
- family Xyridaceae
The morphology-based Cronquist system
Cronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...
did not include an order named Poales, assigning these families to the orders Bromeliales
Bromeliales
The Bromeliales is the botanical name of an order of flowering plants. Such an order has been recognized by a few systems of plant taxonomy, with a various placement. It appears that it always has had the same circumscription:...
, Cyperales
Cyperales
Cyperales is a name for an order of flowering plants. As used in the Engler system and in the Wettstein system it consisted of only the single family...
, Hydatellales
Hydatellales
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]...
, Juncales
Juncales
Juncales is a botanical name for an order of flowering plants. In the Engler system and in the Cronquist system it is circumscribed as:* order Juncales*: family Juncaceae...
, Restionales
Restionales
Restionales is a botanical name for an order of flowering plants. In the Cronquist system it is used for an order and circumscribed as:* order Restionales*: family Flagellariaceae...
and Typhales
Typhales
Typhales is a botanical name for an order of flowering plants. In the Cronquist system the name was used for an order placed in the subclass Commelinidae. The order consisted of :* order Typhales*: family Sparganiaceae...
.
In early systems an order including the grass family did not go by the name Poales but by a descriptive botanical name
Descriptive botanical names
Descriptive botanical names are names that are governed by Article 16 of the International Code of Botanical Nomenclature , which rules that a name above the rank of family may be either descriptive or formed from the name of an included family...
such as Graminales in the Engler system
Engler system
One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler.According to Engler, Syllabus der Pflanzenfamilien the main groups of plants are:* I. divisio Schizophyta* II. divisio Phytosarcodina...
(update of 1964) and in the Hutchinson system
Hutchinson system
A system of plant taxonomy, the Hutchinson system was published inThis classification is according to the 1st Edition in 2 volumes, 1926–1934, Volume 1: Monocotyledonae and Volume 2:Dicotyledonae....
(first edition, first volume, 1926), Glumiflorae
Glumiflorae
Glumiflorae is a descriptive botanical name. It was used in the Wettstein system for an order of flowering plants. The order consisted of one family only:* order Glumiflorae*: family Gramineae...
in the Wettstein system
Wettstein system
A system of plant taxonomy, the Wettstein system recognised the following main groups, according to* I. phylum Schizophyta*::: 1. classis Schizophyceae*::: 2. classis Schizomycetes* II. phylum Monadophyta* III. phylum Myxophyta...
(last revised 1935) or Glumaceae
Glumaceae
Glumaceae is a descriptive botanical name. It was used in the Bentham & Hooker system for the order including the grass family:* order Glumaceae*: family Eriocauleae*: family Centrolepideae*: family Restiaceae...
in the Bentham & Hooker system
Bentham & Hooker system
An early taxonomic system, the Bentham & Hooker system for seed plants was published in :The system recognises the following main groups:*DICOTYLEDONUM POLYPETALARUM*: Series 1. THALAMIFLORÆ*: Series 2. DISCIFLORÆ*: Series 3. CALYCIFLORÆ...
(third volume, 1883).
Uses
The Poales is 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 (PoaceaePoaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
, syn. Gramineae), which includes barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
, maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
, millet
Millet
The millets are a group of small-seeded species of cereal crops or grains, widely grown around the world for food and fodder. They do not form a taxonomic group, but rather a functional or agronomic one. Their essential similarities are that they are small-seeded grasses grown in difficult...
, rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
, and wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
. It is also the largest family in the order, far outnumbering its competitors:
- Poaceae: 12,070 species
- Cyperaceae: 5,500 species
- Bromeliaceae: 3,170 species
- Eriocaulaceae: 1,150 species