Genus Oryza: All kinds of rice

GENUS ORYZA: All kinds of rice

a- Oryza genus in the modern scientific classification

Poaceae = Gramineae =Poa L.
(12 subfamilies with 91 genera)
( with 13 tribes)
(12 tribes with over 20 genera)
Oryza L.
(There are 13 species ) 

In the modern scientific classification the Family Poaceae has about 800 genera with over 10,000 species. Family Poaceae has 12 subfamilies in which subfamily Bambusoideae is one of them with 91 genera.
Subfamily Bambusoideae has 13 tribes and divided into two groups: the Oryzodae (12 tribes) and the Bambusodae (1 tribe).
The Oryzodae has 12 tribes, as following:
1&2-Oryzodae: This group is also separated into subfamily Oryzaceae (13 genera).
3&-4-Tribe Anomochloeae: This tribe is also separated to form subfamily  Anomochlooideae. (1 genera).
5-Tribe Diarrheneae (1 genera).
6-Tribe Ehrharteae (1 genera).
7-Tribe Olyreae (20 genera).
8-Tribe Phaenospermatae (1 genera).
9-Tribe Phareae (4 genera).
10-Tribe Phyllorhachideae (2 genera).
11-Tribe Streptochaeteae (1 genera).
12-Tribe Streptogyneae (1 genera).

A kind of wild rice
-The Tribe Oryzeae: This tribe also forms subfamily Oryzoideae (13 genera).
-The Genus Oryza is a genus of seven to twenty species (depending on many different systems) of rices or grasses in the tribe Oryzeae, within the subfamily Bambusoideae, native to tropical and subtropical regions of Asia, Northern Australia and Africa. They are tall, wetland grasses, growing to 1–2 m tall; the genus includes both annual  and  perennial species.

Harvesting wild rice
Oryza is situated within the tribe Oryzeae, which is characterized morphologically by its single-flowered spikelets whose glumes are almost completely suppressed. In Oryza, two sterile lemma simulate glumes. The tribe Oryzeae is within the subfamily Bambusoideae, a group of Poaceae tribes with certain features of internal leaf anatomy in common. The most distinctive leaf characteristics of this subfamily are the arm cells and fusoid cells found in their leaves. The Bambusoideae are in the family Poaceae, as they all have fibrous root systems, cylindrical stems, sheathing leaves with parallel-veined blades, and inflorescences with spikelets.
While USDA plants lists have only seven species, others have identified up to 17 or over, including sativa, barthii, glaberrima, meridionalis, nivara, rufipogon, punctata, latifolia, alta, grandiglumis, eichingeri, officinalis, rhisomatis, minuta, australiensis, granulata, meyeriana, and brachyantha.
One species, Asian rice (O. sativa), provides 20% of global grain and is a food crop of major global importance. The many species mentioned above are divided into two subgroups within the genus (wild and planting rice).

Colors of some wild rice grains

b-Selected species

-Oryza australiensis- wild rice grows in northern Australia.
-Oryza barthii-wild rice grows in sub-Saharan Africa.
-Oryza glaberrima - African growing rice.
-Oryza latifolia- wild rice in central and south America.
-Oryza longistaminata-Red wild rice in South Africa
-Oryza meridionalis-wild rice in  Western Australia, Northern Queensland.
-Oryza officinalis- wild rice in  Sri Lanka.
-Oryza punctata-wild rice in central and north Africa.
-Oryza rufipogon – wild rice in north America named brownbeard or red rice.
-Oryza sativa - Asian growing rice.
-Oryza nivara - Indian wild rice.

c-Introduction to growing rice

Rice is central to the lives of billions of people around the world. Possibly the oldest domesticated grain (~10,000 years), rice is the staple food for 3.5 billion people and growing rice is the largest single use of land for producing food, covering 9% of the earth's arable land. Rice provides 21% of global human per capita energy and 15% of per capital protein . Calories from rice are particularly important in Asia, especially among the poor, where it accounts for 50-80% of daily caloric intake. As expected, Asia accounts for over 90% of the world's production of rice, with China, India and Indonesia producing the most . Only 6-7% of the world's rice crop is traded in the world market. Thailand, Vietnam, China and the United States are the world's largest exporters. The United States produces 1.5% of the world's rice crop with Arkansas, California and Louisiana producing 80% of the U.S. rice crop.
85% of the rice that is produced in the world is used for direct human consumption . Rice can also be found in cereals, snack foods, brewed beverages, flour, oil, syrup and religious ceremonies to name a few other uses.
Rice belongs to the genus Oryza and has two cultivated and 22 wild species. The cultivated species are Oryza sativa and Oryza glaberrima. Oryza sativa is grown all over the world while Oryza glaberrima has been cultivated in West Africa for the last ~3500 years . Rice is grown under many different conditions and production systems, but submerged in water is the most common method used worldwide. Rice is the only cereal crop that can grow for long periods of time in standing water. 57% of rice is grown on irrigated land, 25% on rainfed lowland, 10% on the uplands, 6% in deepwater, and 2% in tidal wetlands . The flooded rice paddy is a field of aquatic biodiversity, providing a home for fish, plants, amphibians, reptiles, mollusks, and crustaceans, which many of can be used as a means to incorporate protein into the diets of poor and malnourished people in low and middle income countries that farm rice .
Just as rice can be grown in many different environments, it has many characteristics, making one variety more popular in one region of the world than another. Rice can be a short, medium or long grain size. It can also be waxy (sticky) or non-waxy. Some rice varieties are considered aromatic. Rice also comes in many different colors including brown, red, purple and black .
With that brief introduction to rice, we encourage you to explore Gramene's Doorway to Oryza to learn many more specific details about this versatile and very important grass species.
1-Oryza sativa- From Wikipedia, the free encyclopedia
3. IRRI, 2001. Rice Research and Production in the 21st Century.
4. Chaudhary, R., et al., eds., 2001. Speciality rices of the world. Science Publishers, Inc, NH, USA.
5-International Year of Rice, 2004. "Rice and human nutrition" [PDF] factsheet. 

6-Rice Knowledge Bank

Poaceae or Gramineae


Scientific classification

Poa L.
=Poaceae Barnhart
There are 12 subfamilies
Subfamily Anomochlooideae
Subfamily Pharoideae
Subfamily Puelioideae
Subfamily Bambusoideae
Subfamily Pooideae
Subfamily Ehrhartoideae
Subfamily Arundinoideae
Subfamily Centothecoideae
Subfamily Chloridoideae
Subfamily Panicoideae
Subfamily Danthonioideae
Subfamily Micrairoideae

The Poaceae (also known as the Gramineae) is a large and nearly ubiquitous family of monocot flowering plants (Monocotyledons). A monocotyledo-nous family containing the grasses, which number about over 10,000 species in about 800 genera.
Grasses generally have long narrow parallel-veined leaves inserted distichously on a round hollow stem. The inconspicuous flowers are usually borne in a terminal panicle, spike, or raceme consisting of a number of spikelets. Each flower is surrounded by two bracts. The fruit is a *caryopsis.
Members of this family are commonly called grasses, although the term (land) "grass" is also applied to plants that are not in the Poaceae lineage.
The word "grass" has led to plants of the Poaceae often being called "true grasses". Plant communities dominated by Poaceae are called grasslands; grasslands are estimated to comprise 20% of the vegetation cover of the Earth. With about 10,025 currently accepted species in about 668 genera, the Poaceae represent the fifth largest plant family.
Economically they are the most important family of plants as they contain all the cereals, which are man's staple diet. Wheats (Triticum), maize (Zea mays), rice (Oryza saliva), barley (Hordeum vulgare), oats (Avena sativa), rye (Secale cereale), sugar cane (Saccharum officinarum), and sorghums (Sorghum) are all grasses.
Poaceae are often considered to be the most important of all plant families to human economies: it includes the staple food grains and cereal crops grown around the world, lawn and forage grasses, and bamboo, which is widely used for construction throughout east Asia and sub-Saharan Africa. Civilization was founded largely on the ability to domesticate cereal grass crops around the world.


Grasses generally have the following characteristics:
Poaceae have hollow stems called culms, which are plugged (solid) at intervals called nodes, the points along the culm at which leaves arise. Grass leaves are alternate, distichous (in one plane) or rarely spiral, and parallel-veined. Each leaf is differentiated into a lower sheath, which hugs the stem for a distance and a blade with margins usually entire.
-Leaf of Poaceae are hardened with silica phytoliths, which helps discourage grazing animals. In some grasses (such as sword grass), this makes the edges of the grass blades sharp enough to cut human skin. A membranous appendage or fringe of hairs, called the ligule, lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath.
-Flowers of Poaceae are characteristically arranged in spikelets, each spikelet having one or more florets (the spikelets are further grouped into panicles or spikes). A spikelet consists of two (or sometimes fewer) bracts at the base, called glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts called the lemma (the external one) and the palea (the internal). The flowers are usually hermaphroditic (maize, monoecious, is an exception) and pollination is always anemophilous, that is, by wind. The perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, portraying a wheat (Triticum aestivum) spike.
-The fruit of Poaceae is a caryopsis, in which the seed coat is fused to the fruit wall and thus, not separable from it (as in a maize kernel). A tiller a non-seed leaf shoot.

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 grazed or mown regularly without severe damage to the plant.
Three general classifications of growth habit present in grasses: bunch-type (also called caespitose), stoloniferous, and rhizomatous.
The success of the grasses lies in part in their morphology and growth processes, and in part in their physiological diversity. Most of the grasses divide into two physiological groups, using the C3 and C4 photosynthetic pathways for carbon fixation. The C4 grasses have a photosynthetic pathway linked to specialized Kranz leaf anatomy that particularly adapts them to hot climates and an atmosphere low in carbon dioxide.
C3 grasses are referred to as "cool season" grasses, while C4 plants are considered "warm season" grasses; they may be either annual or perennial.
-Annual cool season - wheat, rye, annual bluegrass (annual meadowgrass, Poa annua), and oat.
-Perennial cool season - orchardgrass (cocksfoot, Dactylis glomerata), fescue (Festuca spp), Kentucky bluegrass and perennial ryegrass (Lolium perenne).
-Annual warm season - corn, sudangrass, and pearl millet.
-Perennial warm season - big bluestem, indiangrass, bermudagrass  and  switchgrass.


Biomes dominated by grasses are called grasslands. If only large contiguous areas of grasslands are counted, these biomes cover 31% of the planet's land. Grasslands go by various names depending on location, including pampas, plains, steppes, or prairie.
In addition to their use as forage worldwide by many grazing mammals, such as cattle and other livestock, deer, and elephants, grasses are used as food plants by many species of butterflies and moths.
The evolution of large grazing animals in the Cenozoic has contributed to the spread of grasses. Without large grazers, a clearcut of fire-destroyed area would soon be colonized by grasses and, if there is enough rain, tree seedlings. The tree seedlings would eventually produce shade, which kills most grasses. Large animals, however, trample the seedlings, killing the trees. Grasses persist because their lack of woody stems helps them to resist the damage of trampling.


Until recently, grasses were thought to have evolved around 55 million years ago, based on fossil records. However, recent findings of 65-million-year-old phytolith sresembling grass phytoliths (including ancestors of rice and bamboo) in Cretaceous dinosaur coprolites, may place the diversification of grasses to an earlier date. Indeed, revised dating of the origins of the rice tribe Oryzeae have been led to the suggestion that the date might be pushed back as early as 107 Ma to 129 Ma.
The relationships among the subfamilies Bambusoideae, Ehrhartoideae  and  Pooideae in the BEP clade have been resolved: Bambusoideae and Pooideae are more closely related than Ehrhartoideae. This separation occurred within a relatively short time span (~4 million years).


The grass family is one of the most widely distributed and abundant groups of plants on Earth. They are found on every continent, and are essentially only absent from central Greenland and much of Antarctica.


The most recent classification of the grass family recognizes 12 subfamilies:
1-Anomochlooideae, a small lineage of broad-leaved grasses that includes two genera (Anomochloa, Streptochaeta).
2-Pharoideae, a small lineage of grasses that includes three genera, including Pharus and Leptaspis.
3-Puelioideae, a small lineage that includes the African genus Puelia.
4-Pooideae, including wheat, barley, oats, brome-grass (Bromus), reed-grasses (Calamagrostis) and many lawn and pasture grasses.
5-Bambusoideae, including bamboo.
6-Ehrhartoideae, including rice, wild rice.
7-Arundinoideae, including giant reed, common reed.
8-Centothecoideae, a small subfamily of 11 genera that is sometimes included in Panicoideae.
9-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).
10-Panicoideae, including panic grass, maize, sorghum, sugarcane, most millets,  fonio,  and bluestem grasses.
12-Danthonioideae, including pampas grass.
Depending on the classification followed, the family includes approximately 668 genera.


The Poaceae was named by John Hendley Barnhart in 1895, based on the tribe Poeae (described in 1814 by Robert Brown), and the type genus Poa (described in 1753 byLinnaeus). The term is derived from the Ancient Greek term for "grass".


Grasses are, in human terms, perhaps the most economically important plant family. Grasses' economic importance stems from several areas, including food production, industry, and lawns.

Food production

Agricultural grasses grown for their edible seeds are called cereals. Three cereals – rice, wheat, and maize (corn) – provide more than half of all calories eaten by humans. Of all crops, 70% are grasses. Cereals constitute the major source of carbohydrates for humans and perhaps the major source of protein, and include rice in southern and eastern Asia, maize in Central andSouth America, and wheat and barley in Europe, northern Asia and the Americas.
Sugarcane is the major source of sugar production. Many other grasses are grown for forage and fodder for animal feed, particularly for sheep and cattle, thereby indirectly providing more human calories.


-Grasses are used for construction. Scaffolding made from bamboo 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, and grass roots stabilize the sod of sod houses. Arundo is used to make reeds for woodwind instruments, and bamboo is used for innumerable implements.
Grass fiber can be used for making paper, and for biofuel production.
Phragmites australis (common reed) is important in water treatment, wetland habitat preservation and land reclamation in Afro-Eurasia.

Lawn and ornamental grasses

Grasses are the primary plant used in lawns, which themselves derive from grazed grasslands in Europe. They also provide an important means of erosion control (e.g., along roadsides), especially on sloping land.
Although supplanted by artificial turf in some games, grasses are still an important covering of playing surfaces in many sports, including football, tennis, golf, cricket, and softball/baseball.
Ornamental grasses, such as perennial bunch grasses, are used in many styles of garden design for their foliage, inflorescences, seed heads, and slope stabilization. They are often used in natural landscaping, xeriscaping, contemporary or modern landscaping, wildlife gardening, and native plant gardening.

Econumically important grasses

Economically important grasses:

Leaf and stem crops

Maize (Corn)
Cortaderia spp.
Festuca spp.
Melica spp.
Stipa spp.
Maize (Corn)

Grasses and society

Grasses have long had significance in human society. They have been cultivated as a food source for domesticated animals for up to 10,000 years, and have been used to make paper since the second century AD. Also, the primary ingredient of beer is usually barley or wheat, both of which have been used for this purpose for over 4,000 years.
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.
1-Họ Hòa thảo – Wikipedia tiếng Việt-ọ_Hòa_thảo.
2-Poaceae - Wikipedia, the free encyclopedia .
3-Poaceae - Classification | USDA PLANTS 
4-Poaceae - Definition and More from the Free Merriam-Webster ... .
5-Poaceae (Gramineae) - Flowering Plant Families, UH Botany .