Oryza is a genus of seven to twenty species of 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...

 in the tribe Oryzeae

Oryzeae

Oryzeae is a tribe of flowering plants in the grass family, Poaceae. It contains 12 genera, including both cultivated rice and wild rice .-Genera:* Chikusichloa Koidz.* Hygroryza Nees* Leersia Sw.* Luziola Juss....

, within the subfamily Bambusoideae

Bambusoideae

The Bambusoideae is a subfamily of the true grass family Poaceae, and is characterized by having 3 stigmas and are mostly tree-like. However, there are uncertainties at practically every taxonomic level within the Bambusoideae, and different types of data often result in support for differing...

, native to tropical and subtropical regions of Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, Northern Australia

Northern Australia

The term northern Australia is generally known to include two State and Territories, being Queensland and the Northern Territory . The part of Western Australia north of latitude 26° south—a definition widely used in law and State government policy—is also usually included...

 and Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

. They are tall, wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

 grasses, growing to 1–2 m tall; the genus includes both annual

Annual plant

An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

 and perennial

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 species.

Oryza is situated within the tribe Oryzeae, which is characterized morphologically by its single-flowered spikelets whose glumes

Chaff

Chaff is the dry, scaly protective casings of the seeds of cereal grain, or similar fine, dry, scaly plant material such as scaly parts of flowers, or finely chopped straw...

 are almost completely suppressed. In Oryza, two sterile lemma

Lemma (botany)

Lemma is a phytomorphological term used in botany referring to a part of the spikelet of grasses . It is the lowermost of two chaff-like bracts enclosing the grass floret. It often bears a long bristle called an awn, and may be similar in form to the glumes - chaffy bracts at the base of each...

 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, 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

Oryza sativa

Oryza sativa, commonly known as Asian rice, is the plant species most commonly referred to in English as rice. Oryza sativa is the cereal with the smallest genome, consisting of just 430Mb across 12 chromosomes...

), 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.

Selected species

• Oryza australiensis
• Oryza barthii
  Oryza barthii
  Oryza barthii is a grass in the rice genus Oryza. It is an annual, erect to semierect grass. It has leaves with a short ligule Oryza barthii is a grass in the rice genus Oryza. It is an annual, erect to semierect grass. It has leaves with a short ligule Oryza barthii is a grass in the rice genus...
  
  
• Oryza glaberrima - African rice
• Oryza latifolia
• Oryza longistaminata
  Oryza longistaminata
  Oryza longistaminata A. Chev. & Röhr, can be found in the USA where it is regarded as a noxious weed, and in the Nylsvley Nature Reserve in South Africa...
  
  
• Oryza meridionalis
• Oryza officinalis
• Oryza punctata
• Oryza rufipogon
  Oryza rufipogon
  Oryza rufipogon, known as brownbeard rice and red rice is a member of the genus Oryza. It has a close evolutionary relation to Oryza sativa, the rice grown as a major food crop throughout the world. O...
  
  - brownbeard or red rice
• Oryza sativa
  Oryza sativa
  Oryza sativa, commonly known as Asian rice, is the plant species most commonly referred to in English as rice. Oryza sativa is the cereal with the smallest genome, consisting of just 430Mb across 12 chromosomes...
  
  - Asian rice
• Oryza nivara
  Oryza nivara
  Oryza nivara is a wild progenitor of the cultivated rice Oryza sativa. It is found growing in swampy areas, at edge of pond and tanks, beside streams, in ditches, in or around rice fields...
  
  - Indian wild rice