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Poaceae () or Gramineae () is a large and nearly ubiquitous
family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or social territory, typically subject to the same Politic ...
of
monocotyledon Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. Th ...
ous
flowering plant Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greec ...

flowering plant
s known as grasses. It includes the
cereal A cereal is any Poaceae, grass cultivated (grown) for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, cereal germ, germ, and bran. The term may also refer to the resulting grain ...

cereal
grasses,
bamboo Bamboos are a diverse group of evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in th ...

bamboo
s and the grasses of natural
grassland Grasslands are areas where the vegetation Vegetation is an assemblage of species and the they provide. It is a general term, without specific reference to particular , life forms, structure, extent, or any other specific or geographic ...

grassland
and species cultivated in
lawn A lawn is an area of soil-covered land planted with grass Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people related either by (by recognized birth) or (by mar ...

lawn
s and pasture. The latter are commonly referred to collectively as grass. With around 780
genera Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumscribing) and classifying gr ...
and around 12,000 species, the Poaceae is the fifth-largest plant family, following the
Asteraceae The family (biology), family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the Order (biology), order Asterales. Commonly referred to as the aster, daisy, composite, o ...

Asteraceae
,
Orchidaceae Orchidaceae ( ), common name, commonly called the orchid family, is a diverse and widespread family (biology), family of flowering plants, with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two la ...

Orchidaceae
,
Fabaceae The Fabaceae or Leguminosae,International Code of Nomenc ...

Fabaceae
and
Rubiaceae The Rubiaceae are a family In , family (from la, familia) is a of people related either by (by recognized birth) or (by marriage or other relationship). The purpose of families is to maintain the well-being of its members and of soci ...
. The Poaceae are the most economically important plant family, providing
staple food A staple food, food staple, or simply a staple, is a food Food is any substance consumed to provide Nutrient, nutritional support for an organism. Food is usually of plant, animal or Fungus, fungal origin, and contains essential nutrients, ...

staple food
s from domesticated
cereal A cereal is any Poaceae, grass cultivated (grown) for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, cereal germ, germ, and bran. The term may also refer to the resulting grain ...

cereal
crops such as
maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be ...

maize
,
wheat Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus ''Triticum''; the most widely grown is common wheat Common wheat (''Triticum aestivum'' ...

wheat
,
rice Rice is the seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was relea ...

rice
,
barley Barley (''Hordeum vulgare''), a member of the grass family Poaceae () or Gramineae () is a large and nearly ubiquitous family In human society, family (from la, familia) is a group of people related either by consanguinity (by recogn ...

barley
, and
millet Millets () are a group of highly variable small-seeded grasses, widely grown around the world as cereal crops or grains for fodder and human food. Millets are important crops in the semiarid tropics of Asia and Africa (especially in Indi ...

millet
as well as
feed
feed
for meat-producing animals. They provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other
grain A grain is a small, hard, dry seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double albu ...

grain
s 6%. Some members of the Poaceae are used as building materials (
bamboo Bamboos are a diverse group of evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in th ...

bamboo
,
thatch Thatching is the craft of building a roof A roof is the top covering of a , including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against , , , extremes of , and ...

thatch
, and
straw Straw is an agricultural byproduct A by-product or byproduct is a secondary product derived from a production process, manufacturing Manufacturing is the Production (economics), production of goods through the use of Work (human activity ...

straw
); others can provide a source of
biofuel Biofuel is fuel that is produced through contemporary processes from biomass, rather than by the very slow geological processes involved in the formation of fossil fuels, such as oil. Since biomass technically can be used as a fuel directly (e. ...

biofuel
, primarily via the conversion of maize to
ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ (anatomy), ...

ethanol
. Grasses have
stem Stem or STEM may refer to: Biology * Plant stem, the aboveground structures that have vascular tissue and that support leaves and flowers ** Stipe (botany), a stalk that supports some other structure ** Stipe (mycology), the stem supporting the c ...

stem
s that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath. The leaf grows from the base of the blade, an adaptation allowing it to cope with frequent grazing.
Grassland Grasslands are areas where the vegetation Vegetation is an assemblage of species and the they provide. It is a general term, without specific reference to particular , life forms, structure, extent, or any other specific or geographic ...

Grassland
s such as
savannah A savanna or savannah is a mixed woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats ...

savannah
and
prairie Wheatfield intersection in the Southern Saskatchewan prairies, Canada. Prairies are ecosystem An ecosystem is a community (ecology), community of living organisms in conjunction with the nonliving components of their environment, interact ...
where grasses are dominant are estimated to constitute 40.5% of the land area of the
Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The remaining 70.8% is Water distribution on Earth, covered wi ...

Earth
, excluding
Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an autonomous territory An autonomous administrative division (also referred to as an autonomous area, entity, unit, region, subdivision, or territory) is a subnational administra ...

Greenland
and
Antarctica Antarctica ( or ) is Earth's southernmost continent. It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Oc ...

Antarctica
. Grasses are also an important part of the vegetation in many other habitats, including
wetland A wetland is a distinct ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles ...

wetland
s,
forest A forest is an area of land dominated by tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a ...

forest
s and
tundra In physical geography Physical geography (also known as physiography) is one of the two fields of geography Geography (from Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα ...

tundra
. Though they are commonly called "grasses", groups such as the
seagrasses Seagrasses are the only flowering plant Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek#REDIRECT Greek Greek may refer to: Greece Anyt ...
, rushes and
sedges The Cyperaceae are a family of graminoid In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in t ...
fall outside this family. The rushes and sedges are related to the Poaceae, being members of the
order Order, ORDER or Orders may refer to: * Orderliness Orderliness is a quality that is characterized by a person’s interest in keeping their surroundings and themselves well organized, and is associated with other qualities such as cleanliness a ...
Poales The Poales are a large order Order or ORDER or Orders may refer to: * Orderliness Orderliness is associated with other qualities such as cleanliness Cleanliness is both the abstract state of being clean and free from germs, dirt, trash, or wa ...
, but the seagrasses are members of order
Alismatales The Alismatales (alismatids) are an order of flowering plants including about 4500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Description The Alismatales comprise ...
. However, all of them belong to the
monocot Monocotyledons (), commonly referred to as monocots, (Lilianae Lilianae (also known as Liliiflorae) is a botanical name for a superorder (that is, a rank (botany), rank higher than that of order (biology), order) of flowering plants. Such a supe ...
group of plants.


Etymology

The name Poaceae was given by
John Hendley Barnhart John Hendley Barnhart (October 4, 1871 – November 11, 1949) was an American botanist and author, specializing in biographies of botanists.Gleaston, H. A. John Hendley Barnhart—An appreciation. '' Journal of the New York Botanical Garden'' Augus ...
in 1895, based on the tribe Poeae described in 1814 by Robert Brown, and the type genus ''
Poa ''Poa'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumsc ...

Poa
'' described in 1753 by
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement Ennoblement is the conferring of nobility—the induction of an individual into the noble social class, class. Currently only a few kingdoms still grant nob ...

Carl Linnaeus
. The term is derived from the Ancient Greek πόα (póa, "fodder").


Evolutionary history

Grasses include some of the most versatile
plant life-form Plant life-form schemes constitute a way of classifying plants alternatively to the ordinary species-genus-family scientific classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circu ...
s. They became widespread toward the end of the
Cretaceous The Cretaceous ( ) is a geological period A geological period is one of the several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place. These periods form elements of a hierarchy of division ...

Cretaceous
period, and fossilized
dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 annum, million years ago, although the exact origin and timing of the evolution ...

dinosaur
dung (
coprolite A coprolite (also known as a coprolith) is fossilized A fossil (from Classical Latin: , literally 'obtained by digging') is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples inc ...

coprolite
s) have been found containing
phytolith Phytoliths (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approxim ...
s of a variety that include grasses that are related to modern
rice Rice is the seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was relea ...

rice
and
bamboo Bamboos are a diverse group of evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in th ...

bamboo
. Grasses have adapted to conditions in lush
rain forest Rainforests are forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing and ecological func ...

rain forest
s, dry
desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of ...

desert
s, cold mountains and even intertidal habitats, and are currently the most widespread plant type; grass is a valuable source of food and energy for all sorts of wildlife and organics. A cladogram shows subfamilies and approximate species numbers in brackets: Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Findings of grass-like
phytolith Phytoliths (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approxim ...
s in
Cretaceous The Cretaceous ( ) is a geological period A geological period is one of the several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place. These periods form elements of a hierarchy of division ...

Cretaceous
dinosaur
coprolite A coprolite (also known as a coprolith) is fossilized A fossil (from Classical Latin: , literally 'obtained by digging') is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples inc ...

coprolite
s from the latest Cretaceous (
Maastrichtian The Maastrichtian () is, in the ICS ICS may refer to: Computing * Image Cytometry Standard, a digital multidimensional image file format used in life sciences microscopy * Industrial control system, computer systems and networks used to contr ...
) aged
Lameta Formation The Lameta Formation, also known as the Infratrappean Beds, is a sedimentary geological formation found in Madhya Pradesh, Gujarat, and Maharashtra, India, associated with the Deccan Traps. It is of Maastrichtian age (Late Cretaceous), and is nota ...
of India have pushed this date back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe
Oryzeae Oryzeae is a tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant usage of the term is in the discipline of anthropology. The definition is contested, in part due to conflictin ...
due to findings from the same deposit suggested a date as early as 107 to 129 Mya. Wu, You & Li (2018) described grass microfossils extracted from a specimen of the
hadrosauroid Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and all dinosaurs more closely related to them than to ''Iguanodon''. Their remains have been recovered in Asia, Europ ...
dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 annum, million years ago, although the exact origin and timing of the evolution ...

dinosaur
''
Equijubus ''Equijubus'' (; ''Mǎzōng'' meaning "horse mane" after the area Mǎzōng Mountain 马鬃山 in which it was found), is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification ...
normani'' from the
Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous The Cretaceous ( ) is a that lasted from about 145 to 66 (Mya). It is the t ...
(
Albian The Albian is both an age of the geologic timescale The geologic time scale (GTS) is a system of chronological datingChronological dating, or simply dating, is the process of attributing to an object or event a date in the past, allowing suc ...
) Zhonggou Formation (
China China (), officially the People's Republic of China (PRC; ), is a country in East Asia East Asia is the eastern region of Asia Asia () is Earth's largest and most populous continent, located primarily in the Eastern Hemisphere ...

China
), which were found to belong to primitive lineages within Poaceae, similar in position to the Anomochlooideae. The authors noted that India became separated from
Antarctica Antarctica ( or ) is Earth's southernmost continent. It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Oc ...

Antarctica
, and therefore also all other continents, approximately at the beginning of late
Aptian The Aptian is an age in the geologic timescale The geologic time scale (GTS) is a system of chronological dating that classifies Geology, geological strata (stratigraphy) in time. It is used by geologists, paleontology, paleontologists, and ...
, so the presence of grasses in both India and China during the Cretaceous indicates that the ancestor of Indian grasses must have existed before late Aptian. Wu, You & Li considered the
Barremian The Barremian is an age in the geologic timescale The geologic time scale (GTS) is a system of chronological dating that classifies Geology, geological strata (stratigraphy) in time. It is used by geologists, paleontology, paleontologists, a ...
origin for grasses to be probable. The relationships among the three subfamilies Bambusoideae, Oryzoideae and Pooideae in the BOP clade have been resolved: Bambusoideae and Pooideae are more closely related to each other than to Oryzoideae. This separation occurred within the relatively short time span of about 4 million years. According to
Lester Charles King Lester Charles King (1907–1989) was an English geologist and geomorphologist known for his theories on scarp retreat Scarp retreat is a geological process through which the location of an escarpment changes over time. Typically the cliff is und ...
the spread of grasses in the would have changed patterns of
hillslope evolution Hillslope evolution is the changes in the erosion rates, erosion styles and form of slopes of hills and mountains over time. Conceptual models During most of the 20th century three models of hillslope evolution were widely diffused: slope decline, ...
favouring slopes that are convex upslope and concave downslope and lacking a were common. King argued that this was the result of more slowly acting surface wash caused by carpets of grass which in turn would have resulted in relatively more
soil creep Downhill creep, also known as soil creep or commonly just creep, is a type of creep characterized by the slow, downward progression of rock Rock most often refers to: * Rock (geology) A rock is any naturally occurring solid mass or aggr ...
.


Description

Grasses may be
annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year **Yearbook **Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), a ...
or
perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, thr ...
herbs, generally with the following characteristics (the image gallery can be used for reference): The of grasses, called culms, are usually cylindrical (more rarely flattened, but not 3-angled) and are hollow, plugged at the
nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Node (autonomous system), behaviour fo ...
, where the leaves are attached. Grass
leaves A leaf (plural leaves) is the principal lateral appendage of the vascular plant plant stem, stem, usually borne above ground and specialized for photosynthesis. The leaves, stem, flower and fruit together form the shoot system. Leaves are ...

leaves
are nearly always alternate and distichous (in one plane), and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins. The leaf blades of many grasses are hardened with
silica Silicon dioxide, also known as silica, is an oxide An oxide () is a chemical compound A chemical compound is a chemical substance A chemical substance is a form of matter In classical physics and general chemistry, matter is any su ...

silica
phytolith Phytoliths (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approxim ...
s, which discourage grazing animals; some, such as , are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the
ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf A leaf (plural leaves) is the principal lateral appendage of the vascular plant plant stem, stem, usually borne above g ...
lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath.
Flower A flower, sometimes known as a bloom or blossom Image:Cerisier du Japon Prunus serrulata.jpg, Cherry blossoms in Paris in full bloom. In botany, blossoms are the flowers of stone fruit fruit tree, trees (genus ''Prunus'') and of some other plan ...

Flower
s of Poaceae are characteristically arranged in
spikelet A spikelet, in botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes f ...
s, each having one or more florets. The spikelets are further grouped into . The part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two (or sometimes fewer)
bracts In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are often (but not always) different from foliage leaves. They may be smaller, ...

bracts
at the base, called
glumes Chaff (; ) is the dry, scaly protective casing of the seeds of cereal grain A cereal is any grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses. It includes ...
, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external—the
lemma Lemma may refer to: Language and linguistics * Lemma (morphology), the canonical, dictionary or citation form of a word * Lemma (psycholinguistics), a mental abstraction of a word about to be uttered * Headword, under which a set of related dict ...
—and one internal—the palea. The flowers are usually
hermaphroditic In reproductive biology, a hermaphrodite () is an organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system that embodies the Life#Biology, properties of life ...
maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be ...

maize
being an important exception—and mainly
anemophilous Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including Poaceae, grasses, Cyperaceae, sedges, and Juncaceae, rushes. ...
or wind-pollinated, although insects occasionally play a role. The
perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (botany), calyx (sepals) and the corolla (flower), ...
is reduced to two scales, called ''
lodicule A spikelet, in botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes f ...
s'', that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals. The
fruit In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the ...

fruit
of grasses is a
caryopsis In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the An ...
, in which the seed coat is fused to the fruit wall. A
tiller A tiller or till is a lever used to steer a vehicle. The mechanism is primarily used in watercraft, where it is attached to an outboard motor, rudder post, rudder post or stock to provide leverage in the form of torque for the helmsman to turn t ...
is a leafy shoot other than the first shoot produced from the seed.


Growth and development

Grass blades grow at the base of the blade and not from elongated stem tips. This low growth point evolved in response to grazing animals and allows grasses to be or regularly without severe damage to the plant. Three general classifications of growth habit present in grasses: bunch-type (also called caespitose),
stolon In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanism ...
iferous, and
rhizomatous In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the A ...

rhizomatous
. The success of the grasses lies in part in their morphology and growth processes and in part in their physiological diversity. There are both C3 and C4 grasses, referring to the photosynthetic pathway for carbon fixation. The C4 grasses have a photosynthetic pathway, linked to specialized
Kranz leaf anatomy Kranz may refer to: * Kranz (surname) Kranz is a German language-derived surname; in German the word means ''wreath''. Geographical distribution As of 2014, 61.6% of all known bearers of the surname ''Kranz'' were residents of Germany (frequency ...
, which allows for increased
water use efficiency Water-use efficiency (WUE) refers to the ratio of water used in plant metabolism to water lost by the plant (botanical), plant through transpiration. Two types of water-use efficiency are referred to most frequently: *photosynthesis, photosynthe ...
, rendering them better adapted to hot, arid environments. The C3 grasses are referred to as "cool-season" grasses, while the C4 plants are considered "warm-season" grasses. * Annual cool-season –
wheat Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus ''Triticum''; the most widely grown is common wheat Common wheat (''Triticum aestivum'' ...

wheat
,
rye Rye (''Secale cereale'') is a grass Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people related either by (by recognized birth) or (by marriage or other relationshi ...

rye
, annual bluegrass (annual meadowgrass, ''
Poa annua ''Poa annua'', or annual meadow grass (known in America more commonly as annual bluegrass or simply poa), is a widespread low-growing turfgrass in temperate climates. Notwithstanding the reference to annual plant in its name, perennial bio-types ...

Poa annua
''), and
oat The oat (''Avena sativa''), sometimes called the common oat, is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A spec ...
* Perennial cool-season – orchardgrass (cocksfoot, ''
Dactylis glomerata ''Dactylis glomerata'', also known as cock's-foot, orchard grass, or cat grass (due to its popularity for use with domestic cats The cat (''Felis catus'') is a domestic species In biology, a species is the basic unit of biologica ...

Dactylis glomerata
''), fescue (''
Festuca ''Festuca'' (fescue) is a genus of flowering plants belonging to the grass family (biology), family Poaceae (subfamily Pooideae). They are evergreen or herbaceous plant, herbaceous perennial plant, perennial tufted grasses with a height range of ...

Festuca
'' spp.),
Kentucky bluegrass ''Poa pratensis'', commonly known as Kentucky bluegrass (or blue grass), smooth meadow-grass, or common meadow-grass, is a perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes ...
and perennial ryegrass (''
Lolium perenne ''Lolium perenne'', common name perennial ryegrass, English ryegrass, winter ryegrass, or ray grass, is a grass Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people relat ...

Lolium perenne
'') * Annual warm-season –
maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be ...

maize
, sudangrass, and
pearl millet Pearl millet (''Cenchrus americanus'', commonly known as the synonym ''Pennisetum glaucum''; also known as 'Bajra' in Hindi, 'Sajje' in Kannada, 'Kambu' in Tamil, 'Bajeer' in Kumaoni and 'Gero' in Hausa) is the most widely grown type of millet. ...

pearl millet
* Perennial warm-season –
big bluestem ''Andropogon gerardi'', known commonly as big bluestem, tall bluestem, bluejoint, and turkeyfoot, is a species of tall grass Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of ...
,
Indiangrass ''Sorghastrum nutans'', commonly known as either Indiangrass or yellow Indiangrass, is a North America North America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), con ...
, and
switchgrass ''Panicum virgatum'', commonly known as switchgrass, is a perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to En ...
. Although the C4 species are all in the
PACMAD clade The PACMAD clade (previously PACCMAD, PACCAD, or PACC) is one of two major lineages (or clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyly, monophyletic – that is, composed of ...
(see diagram above), it seems that various forms of C4 have arisen some twenty or more times, in various subfamilies or genera. In the ''
Aristida ''Aristida'' is a very nearly cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaig ...
'' genus for example, one species (''A. longifolia'') is C3 but the approximately 300 other species are C4. As another example, the whole tribe of
Andropogoneae The Andropogoneae, sometimes called the sorghum tribe, are a large tribe of grasses (family Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people related either by ...
, which includes
maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be ...

maize
,
sorghum ''Sorghum'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circum ...

sorghum
,
sugar cane Sugarcane or sugar cane is a species of (often hybrid) tall, perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, ...

sugar cane
, "
Job's tears Job's tears, scientific name ''Coix lacryma-jobi'', also known as adlay or adlay millet, is a tall grain-bearing perennial tropical plant of the family Poaceae (grass family). It is native to Southeast Asia, but introduced to Northern China and I ...
", and
bluestem grass Bluestem can refer to various grasses: * Little bluestem ''Schizachyrium scoparium'', commonly known as little bluestem or beard grass, is a species of North American prairie grass native to most of the contiguous United States (except Califor ...
es, is C4. Around 46 percent of grass species are C4 plants.


Distribution

The grass family is one of the most widely distributed and abundant groups of plants on
Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The remaining 70.8% is Water distribution on Earth, covered wi ...

Earth
. Grasses are found on every continent, including
Antarctica Antarctica ( or ) is Earth's southernmost continent. It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Oc ...

Antarctica
with the presence of
Antarctic hair grass ''Deschampsia antarctica'', the Antarctic hair grass, is one of two flowering plant Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek#REDIRECT ...

Antarctic hair grass
on the
Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martin in Argentina, and originally as the Palmer Peninsula in the US and Graham Land in the United Kingdom, is the northernmost part of the mainland of Antarctica. T ...

Antarctic Peninsula
.


Ecology

Grasses are the
dominant Domination or dominant may refer to: Society * World domination, which is mainly a conspiracy theory * Colonialism in which one group (usually a nation) invades another region for material gain or to eliminate competition * Chauvinism in which a p ...
vegetation in many habitats, including
grassland Grasslands are areas where the vegetation Vegetation is an assemblage of species and the they provide. It is a general term, without specific reference to particular , life forms, structure, extent, or any other specific or geographic ...

grassland
,
salt-marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open Seawater, saltwater or brackish water that is regularly flooded by the tides. It is ...
,
reedswamp A reed bed or reedbed is a natural habitat found in floodplains, waterlogged depressions and estuary, estuaries. Reed beds are part of a Ecological succession, succession from young Reed (plant), reeds colonising open water or wet ground throu ...
and
steppes In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grassland ...
. They also occur as a smaller part of the vegetation in almost every other terrestrial habitat. Grass-dominated
biome A biome is a collection of plants Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respi ...
s are called grasslands. If only large, contiguous areas of grasslands are counted, these biomes cover 31% of the planet's land. Grasslands include
pampas The Pampas (from the qu, pampa, meaning "plain") are fertile South America South America is a continent A continent is any of several large landmasses. Generally identified by convention (norm), convention rather than any st ...

pampas
,
steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grassland ...

steppe
s, and
prairie Wheatfield intersection in the Southern Saskatchewan prairies, Canada. Prairies are ecosystem An ecosystem is a community (ecology), community of living organisms in conjunction with the nonliving components of their environment, interact ...
s. Grasses provide food to many
grazing In agriculture Agriculture is the science, art and practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary Image:Family watching television 1958.jpg, Exercise trends, Increases in sede ...
mammals, as well as to many
species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individu ...
of
butterflies Butterflies are insect Insects (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', m ...

butterflies
and
moth Moths are a paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and all descendants of that ancestor excluding a few—typically only one or two—Monophyly, monophyletic subgroups. The g ...

moth
s. Many types of animals eat grass as their main source of food, and are called ''
graminivore In zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, p ...
s'' – these include
cattle Cattle, taurine cattle, Eurasian cattle, or European cattle (''Bos taurus'' or ''Bos primigenius taurus'') are large domestication, domesticated Cloven hoof, cloven-hooved herbivores. They are a prominent modern member of the subfamily Bovinae ...

cattle
,
sheep Sheep (''Ovis aries'') are quadrupedal, ruminant mammals typically kept as livestock. Like all ruminants, sheep are members of the order (biology), order Artiodactyla, the even-toed ungulates. Although the name ''sheep'' applies to many species ...

sheep
,
horse The horse (''Equus ferus caballus'') is a domesticated Domestication is a sustained multi-generational relationship in which one group of organisms assumes a significant degree of influence over the reproduction and care of another group to ...

horse
s,
rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication ...

rabbit
s and many
invertebrate Invertebrates are animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This includes all animals apart from the chordata, chordate subphylum vertebrate, Vertebra ...
s, such as
grasshopper Grasshoppers are a group of insect Insects (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''comm ...

grasshopper
s and the caterpillars of many brown butterflies. Grasses are also eaten by
omnivorous An omnivore () is an animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. Al ...
or even occasionally by primarily
carnivorous A carnivore , meaning "meat eater" (Latin, ''caro'', genitive ''carnis'', meaning "meat" or "flesh" and ''vorare'' meaning "to devour"), is an organism, animal whose food and energy requirements derive solely from animal Tissue (biology), tissu ...
animals. Grasses dominate certain
biomes A biome is a collection of plants Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to convert Conversion or convert may refer to: Arts, entertainment, and media * Conversion (D ...
, especially
temperate grasslands Temperate grasslands, savannas, and shrublands is a terrestrial biome defined by the World Wide Fund for Nature. The predominant vegetation in this biome consists of grass and/or shrubs. The climate is temperate and ranges from Semi-arid climate, ...
, because many species are adapted to grazing and fire. Grasses are unusual in that the
meristem The meristem is a type of tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa du ...
is near the bottom of the plant; hence, grasses can quickly recover from cropping at the top. The evolution of large grazing animals in the
Cenozoic The Cenozoic ( ; ) is Earth's current geological era An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the ge ...

Cenozoic
contributed to the spread of grasses. Without large grazers, fire-cleared areas are quickly colonized by grasses, and with enough rain, tree seedlings. Trees eventually outcompete most grasses. Trampling grazers kill seedling trees but not grasses.


Taxonomy

There are about 12,000 grass species in about 771 genera that are classified into 12 subfamilies. See the full
list of Poaceae genera The true grasses (Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people related either by (by recognized birth) or (by marriage or other relationship). The purpo ...
. *
Anomochlooideae Anomochlooideae is a subfamily In biological classification In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecul ...
Pilg. ex Potztal, a small lineage of broad-leaved grasses that includes two genera (''Anomochloa'', ''Streptochaeta'') *
Pharoideae Pharoideae is a subfamily of the true grass family (biology), family Poaceae, containing the single tribe Phareae with the two genera ''Leptaspis'' and ''Pharus (plant), Pharus''. Its members grow on the shaded floors of tropics, tropical to warm ...
L.G.Clark & Emmet J. Judziewicz, Judz., a small lineage of grasses of three genera, including ''Pharus'' and ''Leptaspis'' * Puelioideae L.G.Clark, Mikio Kobayashi, M.Kobay., Sarah Mathews, S.Mathews, Russell Edwin Spangler, Spangler & Elizabeth Anne Kellogg, E.A.Kellogg, a small lineage of the African genus ''Puelia'' * Pooideae, including
wheat Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus ''Triticum''; the most widely grown is common wheat Common wheat (''Triticum aestivum'' ...

wheat
,
barley Barley (''Hordeum vulgare''), a member of the grass family Poaceae () or Gramineae () is a large and nearly ubiquitous family In human society, family (from la, familia) is a group of people related either by consanguinity (by recogn ...

barley
,
oat The oat (''Avena sativa''), sometimes called the common oat, is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A spec ...
s, brome-grass (''Bromus''), reed-grasses (''Calamagrostis'') and many lawn and pasture grasses such as Bluegrass (grass), bluegrass (''Poa'') * Bambusoideae, including
bamboo Bamboos are a diverse group of evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in th ...

bamboo
* Ehrhartoideae, including
rice Rice is the seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was relea ...

rice
and wild rice * Aristideae, Aristidoideae, including ''
Aristida ''Aristida'' is a very nearly cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaig ...
'' * Arundinoideae, including giant reed and common reed * Chloridoideae, including the lovegrasses (''Eragrostis'', about 350 species, including teff), dropseeds (''Sporobolus'', some 160 species), finger millet (''Eleusine coracana'' (L.) Gaertn.), and the muhly grasses (''Muhlenbergia'', about 175 species) * Panicoideae, including panic grass,
maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be ...

maize
,
sorghum ''Sorghum'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circum ...

sorghum
, sugarcane, most
millet Millets () are a group of highly variable small-seeded grasses, widely grown around the world as cereal crops or grains for fodder and human food. Millets are important crops in the semiarid tropics of Asia and Africa (especially in Indi ...

millet
s, fonio, "
Job's tears Job's tears, scientific name ''Coix lacryma-jobi'', also known as adlay or adlay millet, is a tall grain-bearing perennial tropical plant of the family Poaceae (grass family). It is native to Southeast Asia, but introduced to Northern China and I ...
", and
bluestem grass Bluestem can refer to various grasses: * Little bluestem ''Schizachyrium scoparium'', commonly known as little bluestem or beard grass, is a species of North American prairie grass native to most of the contiguous United States (except Califor ...
es * Micrairoideae * Danthonieae, Danthonioideae, including Cortaderia, pampas grass


Uses

Grasses are, in human terms, perhaps the most economically important plant family. Their economic importance stems from several areas, including food production, industry, and
lawn A lawn is an area of soil-covered land planted with grass Poaceae () or Gramineae () is a large and nearly ubiquitous family In , family (from la, familia) is a of people related either by (by recognized birth) or (by mar ...

lawn
s. They have been grown as food for domesticated animals for up to 6,000 years and the grains of grasses such as
wheat Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus ''Triticum''; the most widely grown is common wheat Common wheat (''Triticum aestivum'' ...

wheat
, rice, maize (corn) and
barley Barley (''Hordeum vulgare''), a member of the grass family Poaceae () or Gramineae () is a large and nearly ubiquitous family In human society, family (from la, familia) is a group of people related either by consanguinity (by recogn ...

barley
have been the most important human food crops. Grasses are also used in the manufacture of thatching, thatch, paper, fuel, clothing, Building insulation, insulation, timber for fence, fencing, furniture, scaffolding and construction materials, floor matting, #Sports turf, sports turf and basket weaving, baskets.


Food production

Of all crops grown, 70% are grasses. Agricultural grasses grown for their edible seeds are called ''
cereal A cereal is any Poaceae, grass cultivated (grown) for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, cereal germ, germ, and bran. The term may also refer to the resulting grain ...

cereal
s'' or ''grains'' (although the latter term, when used agriculturally, refers to both cereals and legumes). Three cereals—rice, wheat, and maize (corn)—provide more than half of all calories consumed by humans. Cereals constitute the major source of carbohydrates for humans and perhaps the major source of protein; these include rice (in Southern Asia, southern and eastern Asia), maize (in Central America, Central and South America), and wheat and barley (in Europe, northern Asia and the Americas). Sugarcane is the major source of sugar production. Additional food uses of sugarcane include sprouting, sprouted grain, shoots, and rhizomes, and in drink they include sugarcane juice and plant milk, as well as rum, beer, whisky, and Żubrówka, vodka. Bamboo shoots are used in numerous Asian dishes and broths, and are available in supermarkets in various sliced forms, in both fresh, fermented and canned versions. Lemongrass is a grass used as a culinary herb for its citrus-like flavor and scent. Many species of grass are grown as pasture for foraging or as fodder for prescribed livestock feeds, particularly in the case of
cattle Cattle, taurine cattle, Eurasian cattle, or European cattle (''Bos taurus'' or ''Bos primigenius taurus'') are large domestication, domesticated Cloven hoof, cloven-hooved herbivores. They are a prominent modern member of the subfamily Bovinae ...

cattle
,
horse The horse (''Equus ferus caballus'') is a domesticated Domestication is a sustained multi-generational relationship in which one group of organisms assumes a significant degree of influence over the reproduction and care of another group to ...

horse
s, and
sheep Sheep (''Ovis aries'') are quadrupedal, ruminant mammals typically kept as livestock. Like all ruminants, sheep are members of the order (biology), order Artiodactyla, the even-toed ungulates. Although the name ''sheep'' applies to many species ...

sheep
. Such grasses may be cut and stored for later feeding, especially for the winter, in the form of bales of hay or
straw Straw is an agricultural byproduct A by-product or byproduct is a secondary product derived from a production process, manufacturing Manufacturing is the Production (economics), production of goods through the use of Work (human activity ...

straw
, or in silos as silage. Straw (and sometimes hay) may also be used as bedding for animals.


Industry

Grasses are used as raw material for a multitude of purposes, including construction and in the composition of building materials such as cob (material), cob, for insulation, in the manufacture of paper and board such as oriented structural straw board. Grass fiber can be used for making Esparto#Esparto paper, paper,
biofuel Biofuel is fuel that is produced through contemporary processes from biomass, rather than by the very slow geological processes involved in the formation of fossil fuels, such as oil. Since biomass technically can be used as a fuel directly (e. ...

biofuel
production, nonwoven fabrics, and as replacement for glass fibers used in reinforced plastics. Bamboo scaffolding is able to withstand typhoon-force winds that would break steel scaffolding. Larger bamboos and ''Arundo donax'' have stout culms that can be used in a manner similar to timber, ''Arundo'' is used to make reeds for woodwind instruments, and bamboo is used for innumerable implements. ''Phragmites, ''Phragmites australis'''' (common reed) is important for thatching and wall construction of homes in Africa. Grasses are used in water treatment systems, in wetland conservation and land reclamation, and used to lessen the erosional impact of urban storm water runoff.


Lawn and ornamental use

Grasses are the primary plant used in lawns, which themselves derive from grazed
grassland Grasslands are areas where the vegetation Vegetation is an assemblage of species and the they provide. It is a general term, without specific reference to particular , life forms, structure, extent, or any other specific or geographic ...

grassland
s in Europe. They also provide an important means of erosion control (e.g., along roadsides), especially on sloping land. Grass lawns are an important covering of playing surfaces in many sports, including football (soccer), American football, tennis, golf, cricket, softball and baseball. Ornamental grasses, such as perennial bunch grasses, are used in many styles of garden design for their foliage, inflorescences, seed heads. They are often used in natural landscaping, xeriscaping and slope and beach stabilization in contemporary landscaping, wildlife gardening, and native plant gardening. They are used as screens and hedges.


Sports turf

Grass playing fields, courses and pitches are the traditional playing surfaces for many sports, including American football, association football, baseball, cricket, golf, and Rugby football, rugby. Grass surfaces are also sometimes used for horse racing and tennis. Type of maintenance and species of grass used may be important factors for some sports, less critical for others. In some sports facilities, including indoor domes and other places where maintenance of a grass field would be difficult, grass may be replaced with artificial turf, a synthetic grass-like substitute.


Cricket

In cricket, the pitch is the strip of carefully mowed and rolled grass where the bowler bowls. In the days leading up to the match it is repeatedly mowed and rolled to produce a very hard, flat surface for the ball to bounce off.


Golf

Grass on golf courses is kept in three distinct conditions: that of the ''rough'', the ''fairway'', and the ''putting green''. Grass on the fairway is mown short and even, allowing the player to strike the ball cleanly. Playing from the rough is a disadvantage because the long grass may affect the flight of the ball. Grass on the putting green is the shortest and most even, ideally allowing the ball to roll smoothly over the surface. An entire industry revolves around the development and marketing of turf grass varieties.


Tennis

In tennis, grass is grown on very hard-packed soil, and the bounce of a tennis ball may vary depending on the grass's health, how recently it has been mowed, and the wear and tear of recent play. The surface is softer than hard courts and Clay court, clay (other tennis surfaces), so the ball bounces lower, and players must reach the ball faster resulting in a different style of play which may suit some players more than others. Among the world's most prestigious court for grass tennis is Centre Court at Wimbledon, London which hosts the final of the annual Wimbledon Championships in England, one of the four Grand Slam (tennis), Grand Slam tournaments.


Economically important grasses

A number of grasses are invasive species that damage natural ecosystems, including forms of ''Phragmites australis'' which are native to Eurasia but has spread around the world.


Role in society

Grasses have long had significance in human society. They have been cultivated as feed for people and domesticated animals for thousands of years. The primary ingredient of beer is usually barley or wheat, both of which have been used for this purpose for over 4,000 years. In some places, particularly in suburban areas, the maintenance of a grass lawn is a sign of a homeowner's responsibility to the overall appearance of their neighborhood. One work credits lawn maintenance to: In communities with drought problems, watering of lawns may be outdoor water-use restriction, restricted to certain times of day or days of the week. Many US municipalities and homeowners' associations have rules which require lawns to be maintained to certain specifications, sanctioning those who allow the grass to grow too long. The smell of the freshly cut grass is produced mainly by cis-3-Hexenal. Some common aphorisms involve grass. For example: * "The grass is always greener on the other side" suggests an alternate state of affairs will always seem preferable to one's own. * "Don't let the grass grow under your feet" tells someone to get moving. * "A snake in the grass" means dangers that are hidden. * "When elephants fight, it is the grass which suffers" tells of bystanders caught in the crossfire. A folk myth about grass is that it refuses to grow where any violent death has occurred.Olmert, Michael (1996). ''Milton's Teeth and Ovid's Umbrella: Curiouser & Curiouser Adventures in History'', p. 208. Simon & Schuster, New York. .


Image gallery

File:Ruwbeemdgras Poa trivialis ligula.jpg, Leaves of ''Poa trivialis'' showing the ligules File:Bamboo DSCN2465.jpg, Bamboo stem and leaves, nodes are evident File:Chasmanthium latifolium-spikelet.jpg, A ''Chasmanthium latifolium'' spikelet File:En Spica spiculae.png, Wheat spike and spikelet File:En Aperta.png, Spikelet opened to show caryopsis File:Harestail grass.jpg, Harestail grass File:Grass.jpg, Grass File:Saccharum-officinarum2.JPG, Sugarcane (''Saccharum officinarum'') File:Bromus hordeaceus unten.jpeg, Roots of ''Bromus hordeaceus'' File:Ohra.jpg, Barley mature spikes (''Hordeum vulgare'') File:Koeh-283.jpg, Illustration depicting both staminate and pistillate flowers of maize (''Zea mays'') File:Flowering Grass.JPG, A grass flower head (meadow foxtail) showing the plain-coloured flowers with large anthers. File:Grass Anthers.JPG, Anthers detached from a meadow foxtail flower File:Setaria verticillata W IMG 1084.jpg, ''Setaria verticillata'', bristly foxtail File:Setaria verticillata W IMG 1083.jpg, ''Setaria verticillata'', bristly foxtail File:Oryza sativa in Kadavoor.jpg, ''Oryza sativa'', Kerala, India


See also

* Agrostology * Forb *GrassBase *
PACMAD clade The PACMAD clade (previously PACCMAD, PACCAD, or PACC) is one of two major lineages (or clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyly, monophyletic – that is, composed of ...


References


External links

*
Need a Definition of Grass?

Vegetative Key to Grasses

Poaceae
a
''The Plant List''


a
''The Families of Flowering Plants (DELTA)''


at th
''Angiosperm Phylogeny Website''

''Poaceae Classification''
from the onlin
''Catalogue of New World Grasses''

Poaceae
at the onlin
''Guide to the Flora of Mongolia''

Poaceae
at the onlin
''Flora of Taiwan''

Poaceae
at the onlin
''Flora of Pakistan''

Poaceae
at the onlin
''Flora of Zimbabwe''

Poaceae
at the onlin
''Flora of Western Australia''
* Grasses of Australia (AusGrass2) – http://ausgrass2.myspecies.info/
Gramineae
at the onlin
''Flora of New Zealand''

NZ Grass Key
An Interactive Key to New Zealand Grasses a
''Landcare Research''

The Grass Genera of the World
a
''DELTA intkey''



''GrassWorld''
{{Authority control Poaceae, Poales families Grasses, Grasslands Plant life-forms Plants by habit Extant Early Cretaceous first appearances