Oryza glaberrima

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Oryza glaberrima
Oryza glaberrima seeds.jpg
Seeds of Oryza glaberrima
Scientific classification
Kingdom: Plantae
Division: Angiosperms
Class: Monocots
Subclass: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Bambusoideae
Tribe: Oryzeae
Genus: Oryza
Species: O. glaberrima
Binomial name
Oryza glaberrima
Oryza glaberrima distribution.svg
The range of Oryza glaberrima.

Oryza glaberrima, commonly known as African rice, is one of the two domesticated rice species.[1] It was first domesticated and grown in West Africa,[2] and was brought to the Americas by enslaved West African rice farmers.[3] It is now largely a subsistence crop, rarely sold in markets even in West Africa.[4]

While it has been partly replaced by higher-yielding Asian rice,[2] and the number of varieties grown is declining,[1] it persists, making up an estimated 20%[5] of rice grown in West Africa. By comparison to Asian rice, it is hardy, pest-resistant, low-labour, suited to a variety of African conditions,[1] filling, and has a distinct nutty flavour.[5] It is also grown for cultural reasons; for instance, it is sacred to awasena followers among the Jola people,[6] and is a heritage variety in the United States.[7]

Crossbreeding between African and Asian rice is difficult, but there exist some crosses.[8][9][10]


Growing Oryza glaberrima along the Niger River, where the species was first domesticated.

Humans have independently domesticated two different rice species. African rice was domesticated from wild African rice, Oryza barthii, while Asian rice (Oryza sativa), was domesticated from wild Asian rice, Oryza rufipogon.

Oryza barthii still grows wild in Africa, in a wide variety of open habitats. The Sahara was formerly wetter, with massive paleolakes in what is now the Western Sahara. As the climate dried, the wild rice retreated and probably became increasingly domesticated as it relied on humans for irrigation. Rice growing in deeper, more permanent water became floating rice[5]

Areas named in the text; rivers and lakes are unfortunately not shown

It is believed to have been domesticated 2000–3000 years ago in the inland delta of the Upper Niger River, in what is now Mali.[1][2] It then spread through West Africa. It has also been recorded off the east coast of Africa, in the Zanzibar Archipelago.[5]

Wild rice seedheads shatter, scattering the rice grains to seed the next generation. Domestic rice does not shatter, making the grains easy for humans to gather. A mutation that caused rice not to shatter would probably have been the beginning of domestication.

Ibn Baṭṭūṭa recorded rice couscous in the area of present-day Mali in 1350.[citation needed]

A pond in the foreground with a steep embankment blocking its spreading to the left and with trees in the background
Dikes protect the rice paddy fields from saltwater; the irrigation skims the freshwater layer off the high tide.[11] Similar delta cultivation techniques were used going back to at least the 15th century[12] Karabane, Senegal, 2008.

In the late fifteenth and sixteenth centuries, the Portuguese sailed to the Southern Rivers area in West Africa and wrote that the land was rich in rice. "[T]hey said they found the country covered by vast crops, with many cotton trees and large fields planted in rice … the country looked to them as having the aspect of a pond (i.e., a marais)”. The Portuguese accounts speak of the Falupo Jola, Landuma, Biafada, and Bainik growing rice. André Álvares de Almada wrote about the dike systems used for rice cultivation,[1] from which modern West African rice dike systems are descended.

Similar dyke in Hampton, South Carolina, United States, in 2010, long abandoned and reclaimed by woodland[12]

African rice was brought to the Americas with the transatlantic slave trade, arriving in Brazil probably by the 1550s[3] and in the U.S. in 1784.[13][dubious ] The seed was carried as provisions on slave ships,[3] and the technology and skills needed to grow it were brought by enslaved rice farmers. Newly imported African slaves were marketed (and sometimes even trained) for their rice-growing skills, as the high price of rice made it a major cash crop.[11] The tolerance of African rice for brackish water meant it could be grown on coastal deltas,[12][14] as it was in West Africa.

There are numerous stories about how the rice came to North America,[15] including a slave smuggling grains in her hair[3] and a ship driven in to trade by a storm.[12][16] African rice is a rare crop in Brazil, Guyana, El Salvador and Panama, but it is still occasionally grown there.[5] There are also native South American rices, which makes it hard to recognize the arrival of African rice in histories.[3]

Asian rice came to West Africa in the late 1800s, and by the late twentieth century had substantially supplanted native African rice. However, African rice was still used in specific, often marginal habitats, and preferred for its taste[1][5][17][better source needed] Farmers may grow African rice to eat and Asian rice to sell, as African rice is not exported.

The 2007 food price shocks drove efforts to raise rice production. Rice-going regions of Africa are generally net rice importers (partly due to a lack of good local rice-processing capacity) so price increases hurt.[18] Among the efforts to increase yield was the adoption of nerica cultivars, crossbred to specifications from local farmers using African rice varieties provided by local farmers.[1] These were bred during the 1990s and released in the early 20th century.[8] Results so far have been mixed; the nerica varieties are less hardy and more labour-intensive, and effects on real-world yields vary. Subsidies of nerica seeds have also been criticized for encouraging the loss of native varieties and reducing the independence of farmers.[10]


African rice in its inedible husk
The same rice, dehusked (whole brown rice)
The same rice, with almost all the bran and germ removed to make white rice

Multiple varieties of African rice are often grown so that the harvest is staggered. In this way, the harvest can be eaten fresh. Freshly harvested rice is moist, and can be puffed in fire, and eaten. Fried rice have browny color when fried this is because of the husk that is green in color when heated turns brown.[clarification needed][citation needed]

African rice can be prepared in much the same way as Asian rice, but has a distinct nutty flavour, for which it is favoured in West Africa.[1][19] African rice grains are often reddish in colour; some varieties are strongly aromatic,[5] other, like Carolina Gold, are not at all aromatic.[13]

African rice is used medicinally for multiple purposes.[19]



African rice is a tall rice plant, usually under 120 cm but up to five meters for floating varieties, which may also branch and root from higher stem nodes.[5] Generally, African rice has small, pear-shaped grain, reddish bran and green to black hulls, straight, simply-branched panicles, and short, rounded ligules. There are, however, exceptions, and it can be hard to distinguish from Asian rice.[1][5] For complete certainty, a genetic test can be used.


African rice is well adapted to the African environment. It is drought- and deep-water-resistant, and tolerates fluctuations in water depth, iron toxicity, infertile soils, severe climatic conditions, and human neglect better than Asian rice.[1][20] Some varieties also mature more quickly, and may be sown directly on higher ground, eliminating the need to transplant seedlings.[1] Most is rain-watered, and the soil is often not cultivated.[5]

African rice has profuse vegetative growth, which smothers weeds. It exhibits better resistance to various rice pests and diseases, such as blast disease, African rice gall midge (Orseolia oryzivora), parasitic nematodes (Heterodera sacchari and Meloidogyne spp.), rice stripe necrosis virus, rice yellow mottle virus, and the parasitic plant Striga.[8][20]

Yield and processing[edit]

Most African rices shatter more than Asian rices, possibly because they haven't been domesticated for as long. A few varieties of African rice are as resistant to shattering as shatter-resistant Asian varieties, but most are not; on average, about half of the grains are scattered and lost. This is why yield is lower; when the heads of African rice are bagged before they become ripe, so that the shattered grains are caught in paper bags, the yield of African rice is the same as the yield of Asian rice.[20]

Like other grains, rice may lodge, or fall over, when grain heads are full. African rice's greater height and weaker stems makes it more likely to lodge, although it also lets it survive in deep water, and makes it easier to harvest. African rice tend to elongate rapidly if completely submerged, which is not advantageous in regions prone to short floods, as it weakens the plant.[5][21]

The grains of African rice are more brittle than those of Asian rice. The grains are more likely to break during industrial polishing.[7] Broken rice is widely used in West Africa, and some cookbooks from the region will suggest manually breaking the grains for certain recipes,(example) but most broken rice eaten is from Asian rice, about 16% of which is broken in processing.

The genome of O. glaberrima has been sequenced, and was published in 2014.[2] This allowed genomic as well as physiological comparison with related species, and identified some effects of some genes.[22][23]


African and Asian rice do not readily interpollinate, even under controlled conditions, and when they do, the offspring are very rarely fertile. Even the fertile crossbred offspring have low fertility.[8]

Crossbreeding seems to have succeeded in at least one area of Maritime Guinea, as some varieties there show crossbred genes.[9]

More recently, the nerica cultivars (new rice for Africa) have been developed using green revolution techniques like embryo rescue.[8] Over 3000 crosses were made as part of the NERICA program.[8] Breeding within the species is easier, and there are uncounted numbers of African rice varieties, although the majority may have been lost.[1] A similar crossed variety was bred in the United States in 2011,[15] and work is being done on crosses with Indian rice varieties.[8]


African cultivars[edit]

There are a great many varieties of African rice. In the 1960s older women in Jipalom (a village in the Ziguinchor Region) could unhesitatingly name more than ten varieties of African rice that were no longer planted, besides the half-dozen that were then still being planted. Each woman would plant multiple different varieties, to suite varying microhabitats and to stagger the harvest.[1] A 2006 survey showed that a village typically cultivated 25 varieties of rice; an individual household would on average have 14 varieties and grow four per year;[10] this, however, is down from the seven to nine varieties per woman that was average in previous decades. Women, who are traditionally responsible for the seeds, trade them often over long-distance networks.[1]

Varieties, each with subtypes, include:[1]

  • aspera
  • ebenicolorata
  • evoluta
  • rigida
  • rustica

The cultivars the Africa Rice Center calls TOG 12303 and TOG 9300 have low shattering, and thus yields comparable with low-shattering Asian rice varieties.[20]

Scientists from the Africa Rice Center managed to cross-breed African rice with Asian rice varieties to produce a group of interspecific cultivars called New Rice for Africa (NERICA).[24]

American cultivars[edit]

See also Rice production in the United States.

Carolina Gold is an heirloom cultivar grown in the early United States, sometimes known as golden-seed rice for the colour of its grains.[13]

Long-grain gold-seed rice boasted grains 5/12ths of an inch long (up from 3/8ths of an inch), and was brought to market by planter Joshua John Ward in the 1840s. Despite its popularity, the variety was lost in the American Civil War.[13]

Charleston Gold was released in 2011 and is a crossbreed of Carolina Gold and two Oryza sativa breeding lines called IR64 (Indica[25]) and IR65610-24-3-6-3-2-3, which raised the yield, shortened the stem, and added an aromatic quality to the rice.[13]


  1. ^ a b c d e f g h i j k l m n o Linares, Olga F. (2002-12-10). "African rice (Oryza glaberrima): History and future potential". Proceedings of the National Academy of Sciences. 99 (25): 16360–16365. doi:10.1073/pnas.252604599. ISSN 1091-6490. PMID 12461173. Retrieved 2016-08-09. 
  2. ^ a b c d Wang, Muhua; Yu, Yeisoo; Haberer, Georg; Marri, Pradeep Reddy; Fan, Chuanzhu; Goicoechea, Jose Luis; Zuccolo, Andrea; Song, Xiang; Kudrna, Dave; Ammiraju, Jetty S. S.; Cossu, Rosa Maria; Maldonado, Carlos; Chen, Jinfeng; Lee, Seunghee; Sisneros, Nick; de Baynast, Kristi; Golser, Wolfgang; Wissotski, Marina; Kim, Woojin; Sanchez, Paul; Ndjiondjop, Marie-Noelle; Sanni, Kayode; Long, Manyuan; Carney, Judith; Panaud, Olivier; Wicker, Thomas; Machado, Carlos A.; Chen, Mingsheng; Mayer, Klaus F. X.; Rounsley, Steve; Wing, Rod A. (2014-07-27). "The genome sequence of African rice (Oryza glaberrima) and evidence for independent domestication". Nature Genetics. 46 (9): 982–988. doi:10.1038/ng.3044. ISSN 1061-4036. Retrieved 2016-08-09. 
  3. ^ a b c d e Judith A. Carney (2004), "'With Grains in Her Hair': Rice in Colonial Brazil" (PDF), Slavery and Abolition, Frank Cass, London, 25 (1), pp. 1–27 
  4. ^ Ikhioya, Sunny; Oritse, Godwin (2013-10-07). "Smuggled rice floods Nigerian market, as merchants suffer losses". Vanguard. 
  5. ^ a b c d e f g h i j k Plant Resources of Tropical Africa, PROTA4U database, Oryza glaberrima Steud 
  6. ^ Thiam, Pierre; Sit, Jennifer (2015). Senegal: Modern Senegalese Recipes from the Source to the Bowl (Chapter extract: A System of Rice Production, Broken). Lake Isle Press. 
  7. ^ a b Carney, Judith Ann (2009-06-30). Black Rice: The African Origins of Rice Cultivation in the Americas. Harvard University Press. ISBN 978-0-674-02921-7. 
  8. ^ a b c d e f g Sarla, N.; Swamy, B. P. Mallikarjuna (2005-09-25). "Oryza glaberrima: A source for the improvement of Oryza sativa". ResearchGate. 89 (25). ISSN 0011-3891. Retrieved 2016-08-10. 
  9. ^ a b Barry, M. B.; Pham, J. L.; Noyer, J. L.; Billot, C.; Courtois, B.; Ahmadi, N. (2007-01-04). "Genetic diversity of the two cultivated rice species (O. sativa & O. glaberrima) in Maritime Guinea. Evidence for interspecific recombination". Euphytica. 154 (1-2): 127–137. doi:10.1007/s10681-006-9278-1. ISSN 0014-2336. Retrieved 2016-08-10. 
  10. ^ a b c GRAIN (NGO) (2009), Nerica: another trap for small farmers in Africa (PDF) 
  11. ^ a b Jean M. West. "Rice and Slavery: A Fatal Gold Seede". Slavery in America Organization. Archived from the original on January 1, 2007. Retrieved 24 June 2013. 
  12. ^ a b c d The Rice Diversity Project. "Slavery on South Carolina Rice Plantations: The Migration of People and Knowledge in Early Colonial America" (PDF). 
  13. ^ a b c d e Charleston Gold: A Direct Descendant of Carolina Gold, by David S. Shields. Rice Paper, Vol. 5 No. 1
  14. ^ http://ldhi.library.cofc.edu/exhibits/show/forgotten_fields/decline_in_inland_rice
  15. ^ a b David S. Shields. "The Golden Seed" (PDF). Rice Paper. 5 (1). 
  16. ^ Storm story for Carolina Gold
  17. ^ Ologbon, O. A. C.; Ikheloa, E. E.; Akerele, E. O. (2012). "Adoption of 'Ofada'rice variety and technical efficiency of rice-based production systems in Ogun state, Nigeria" (PDF). World Journal of Agricultural Sciences. 8 (6): 624–631. Retrieved 2016-08-10. 
  18. ^ S.A.Tiamiyu,S.A, Usman, A., Gbanguba, A.U., Ukwungu, M.N. and A.A. Ochigbo (2010), Assessment of quality management techniques: Toward improving competitiveness of Nigerian rice (PDF), Bamako, Mali 
  19. ^ a b "Oryza glaberrima (African rice)". Plants & Fungi At Kew. Retrieved 2016-08-10. 
  20. ^ a b c d Montcho, D.; Futakuchi, K.; Agbangla, C.; Fofana, M.; Dieng, I. (2013-01-01). "Yield loss of Oryza glaberrima caused by grain shattering under rainfed upland conditions". International Journal of Biological and Chemical Sciences. 7 (2): 535–543. doi:10.4314/ijbcs.v7i2.10. ISSN 1997-342X. Retrieved 2016-08-09. 
  21. ^ Woolhouse, Harold William (1979). Advances in botanical research. Vol. 7 Vol. 7. London: Academic Press. ISBN 978-0-12-005907-2. 
  22. ^ Zhang, Qun-Jie; Zhu, Ting; Xia, En-Hua; Shi, Chao; Liu, Yun-Long; Zhang, Yun; Liu, Yuan; Jiang, Wen-Kai; Zhao, You-Jie; Mao, Shu-Yan; Zhang, Li-Ping; Huang, Hui; Jiao, Jun-Ying; Xu, Ping-Zhen; Yao, Qiu-Yang; Zeng, Fan-Chun; Yang, Li-Li; Gao, Ju; Tao, Da-Yun; Wang, Yue-Ju; Bennetzen, Jeffrey L.; Gao, Li-Zhi (2014-11-18). "Rapid diversification of five Oryza AA genomes associated with rice adaptation". Proceedings of the National Academy of Sciences. 111 (46): –4954–E4962. doi:10.1073/pnas.1418307111. ISSN 1091-6490. PMID 25368197. Retrieved 2016-08-10. 
  23. ^ Gutiérrez, Andrés Gonzalo; Carabalí, Silvio James; Giraldo, Olga Ximena; Martínez, César Pompilio; Correa, Fernando; Prado, Gustavo; Tohme, Joe; Lorieux, Mathias (2010). "Identification of a Rice stripe necrosis virus resistance locus and yield component QTLs using Oryza sativa × O. glaberrima introgression lines". BMC Plant Biology. 10: 6. doi:10.1186/1471-2229-10-6. ISSN 1471-2229. Retrieved 2016-08-10. 
  24. ^ Jones, Monty P.; Dingkuhn, Michael; Aluko/snm>, Gabriel K.; Semon, Mandé (1997-03-01). "Interspecific Oryza Sativa L. X O. Glaberrima Steud. progenies in upland rice improvement". Euphytica. 94 (2): 237–246. doi:10.1023/A:1002969932224. ISSN 0014-2336. 
  25. ^ Datta, Karabi; Datta, Swapan Kumar (2006). "Indica rice (Oryza sativa, BR29 and IR64)". Methods in Molecular Biology (Clifton, N.J.). 343: 201–212. doi:10.1385/1-59745-130-4:201. ISSN 1064-3745. PMID 16988345. 

Further reading[edit]