Oryza

Oryza is a genus of plants in the grass family.<ref>Linnaeus, Carl von. 1753. Species Plantarum 1: 333. in Latin</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It includes the major food crop rice (species Oryza sativa and Oryza glaberrima). Members of the genus grow as tall, wetland grasses, growing to Template:Convert tall; the genus includes both annual and perennial species.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Oryza is situated in 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 in subfamily Ehrhartoideae,<ref name=Kellogg>Template:Cite journal</ref> 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.<ref>Heywood, V.H. Flowering Plants of the World 1993 Oxford University Press</ref>Template:Verify source

One species, Asian rice (O. sativa), provides 20% of global grain and is a food crop of major global importance. The species are divided into two subgroups within the genus.

Species

Inside the genus Oryza, species can be divided by their genomes types. They include the diploid (2n = 24) Template:Visible anchor of cultivated rice and their relatives, Template:Visible anchor, Template:Visible anchor, Template:Visible anchor, Template:Visible anchor and Template:Visible anchor as well as the tetraploid (4n = 48) Template:Visible anchor, Template:Visible anchor, Template:Visible anchor, Template:Visible anchor and Template:Visible anchor. Species of the same genome type cross easily, while hybridizing different types requires techniques like embryo rescue.<ref name="phylo">Template:Cite journal</ref><ref name=genome-phylo>Template:Cite journal</ref>

Over 300 names have been proposed for species, subspecies, and other infraspecific taxa within the genus. Published sources disagree as to how many of these should be recognized as distinct species. The following follows the World Checklist maintained by Kew Garden in London.<ref name=POWO>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

1. Oryza australiensis Template:Au (EE) – Australia
2. Oryza barthii Template:Au (AA) – tropical Africa
3. Oryza brachyantha Template:Au (FF) – tropical Africa
4. Oryza coarctata Template:Au (KKLL) – India, Pakistan, Bangladesh, Myanmar
5. Oryza eichingeri Template:Au (CC) – tropical Africa, Sri Lanka
6. Oryza glaberrima Template:Au (AA) – African rice – tropical Africa
7. Oryza grandiglumis Template:Au (CCDD) – Brazil, Venezuela, Fr Guiana, Colombia, Peru, Bolivia
8. Oryza latifolia Template:Au (CCDD) – Latin America + West Indies from Sinaloa + Cuba to Argentina
9. Oryza longiglumis Template:Au (HHJJ) – New Guinea
10. Oryza longistaminata Template:Au (AA) – Madagascar, tropical + southern Africa
11. Oryza meyeriana Template:Au (GG) – China, Indian Subcontinent, Southeast Asia
12. Oryza minuta Template:Au (BBCC) – Himalayas, Southeast Asia, New Guinea, Northern Territory of Australia
13. Oryza neocaledonica Template:Au (GG) – New Caledonia
14. Oryza officinalis Template:Au (CC) – China, Indian Subcontinent, Southeast Asia, New Guinea, Australia
15. Oryza punctata Template:Au (BB) – Madagascar, tropical + southern Africa
16. Oryza ridleyi Template:Au (HHJJ) – Southeast Asia, New Guinea
17. Oryza rufipogon Template:Au (AA) – brownbeard or red rice – China, Indian Subcontinent, Southeast Asia, New Guinea, Australia
18. Oryza sativa Template:Au (AA) – Asian rice – China, Indian Subcontinent, Japan, Southeast Asia; naturalized many places
19. Oryza schlechteri Template:Au (HHKK) – New Guinea

Formerly included

Many species are nowTemplate:Vague regarded as better suited to other genera:<ref name=POWO/>

• Echinochloa
• Leersia
• Maltebrunia
• Potamophila
• Prosphytochloa
• Rhynchoryza

See also

• Specialized metabolism in Oryza