Oryza glaberrima Steud.

First published in Syn. Pl. Glumac. 1: 3 (1853)
This species is accepted
The native range of this species is W. Tropical Africa to Chad. It is an annual and grows primarily in the seasonally dry tropical biome.

Descriptions

Morphology General Habit
Annual. Culms erect, or geniculately ascending; 90-150 cm long. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1.5-2 mm long; truncate. Leaf-blades 20-30 cm long; 10-15 mm wide. Leaf-blade apex acute.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; linear; equilateral, or nodding; 15-25 cm long. Primary panicle branches appressed, or ascending. Panicle branches angular; scaberulous. Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear; angular; scaberulous; tip cupuliform; bibracteate.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; laterally compressed; 7-8 mm long; persistent on plant. Spikelet callus glabrous.
Fertile
Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; laterally compressed; 7-8 mm long; persistent on plant. Spikelet callus glabrous.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes both absent or obscure.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets similar; barren; without significant palea. Lemma of lower sterile floret lanceolate; 2-4 mm long; 0.3-0.5 length of spikelet; membranous; 1 -veined; without lateral veins; acute. Lemma of upper sterile floret lanceolate; 2-4 mm long; 1 length of lower sterile floret; membranous. Fertile lemma elliptic; laterally compressed; 7-8 mm long; coriaceous; keeled; 5 -veined. Lemma midvein eciliate. Lemma surface reticulate; glabrous. Lemma margins involute. Lemma apex rostrate; muticous. Palea elliptic; 1 length of lemma; coriaceous; 3 -veined; 1-keeled. Palea keels smooth. Palea apex acute.
Morphology Reproductive morphology Flowers
Lodicules 2; lanceolate; membranous. Anthers 6. Stigmas 2.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp. Disseminule comprising a floret.
Distribution
Africa: west tropical and west-central tropical. Asia-temperate: China.
Reference
Oryzeae. WDC.
[GB]

Kew Species Profiles

General Description

There are only two species of cultivated rice in the world: Asian rice (Oryza sativa) and African rice (Oryza glaberrima). African rice is native to West Africa, where it is cultivated as a foodcrop. It is known for its hardiness and its ability to compete with weeds, pests, infertile soils and human neglect. However, increasingly African rice is being replaced by the introduced Asian varieties of Oryza sativa, which produce a higher yield than African rice, shatter less easily and have a softer grain that is easier to mill.

African rice is still an important crop for small-scale farmers who grow it for its nutty flavour and other culinary qualities. It is also used in a ritualistic context and as a treatment in African traditional medicine.

Species Profile
Geography and distribution

Oryza glaberrima is native to West Africa and grows in the region extending from the delta of the River Senegal to Lake Chad in the east. The most intensive areas of cultivation of African rice are the floodplains of northern Nigeria, the inland delta of the Niger River, parts of Sierra Leone and Ghana.

African rice was introduced to the New World during the days of the slave trade and today is cultivated in parts of Brazil, Guyana, El Salvador and Panama.  Oryza glaberrima  is thought to have been domesticated from its wild ancestor  Oryza barthii  around 1,500 BC in the inland delta of the Niger River. Today  Oryza barthii  can be found growing wild in parts of Africa.

Description

Overveiw:   Oryza glaberrima  is an annual with erect stems up to 90-150 cm long. The sheaths which enclose the stems are smooth and hairless.

Leaves: The leaf blades are 20-30 cm long and 10-15 mm wide and pointed at the tip.

Flowers: The inflorescence is a panicle (an extensively branched inflorescence) 15-25 cm long. The spikelets (clustered units of flowers and bracts) are solitary. The fertile spikelets comprise two sterile florets at the base and one fertile floret. The spikelets are about 8 mm long and remain on the plant when mature. The glumes (empty bracts that enclose the florets) are absent or obscure. The flower contains two lance-shaped (lanceolate) lodicules (small structures at the base of the stamens). Each flower has six anthers and two stigmas.

Fruits: The fruit is a caryopsis (a dry fruit where the fruit wall is attached to the seed).

Uses

African rice is a staple food which can be prepared in similar ways to Asian rice ( Oryza sativa ). Broken grains are used to feed chicken and other livestock. Some cultures in West Africa, such as the Jola of southern Senegal grow African rice to be used in traditional ceremonies and rituals.

African rice also has many medicinal benefits: for example, in the Central African Republic the root is eaten raw as a remedy for diarrhoea. 

Crop wild relatives of African rice

The Millennium Seed Bank and the Global Crop Diversity Trust are engaged in a ten-year project, called 'Adapting Agriculture to Climate Change'. The project aims to protect, collect and prepare the wild relatives of 29 key food crops, including African rice, so that they are available to pre-breeders for the development of new varieties that are more resilient to the effects of climate change.

Millennium Seed Bank: Seed storage

The Millennium Seed Bank Partnership aims to save plants worldwide, focusing on those plants which are under threat and those which are of most use in the future. Once seeds have been collected they are dried, packaged and stored at -20°C in Kew's Millennium Seed Bank vault.

Description of seeds:  Average weight of 1,000 seeds = 26.5 g

Number of seed collections stored in the Millennium Seed Bank:  One

Seed storage behaviour:  Orthodox (the seeds of this plant can be dried to a low moisture content without significantly reducing their viability which means they are suitable for long-term frozen storage)

Germination testing:  Successful

This species at Kew

Pressed and dried specimens ofAfrican rice are held in Kew's Herbarium, where they are available to researchers by appointment. Details and images of some of these specimens can be seen online in Kew's Herbarium Catalogue.

Distribution
Ghana, Niger, Sierra Leone
Ecology
African rice grows best on fertile alluvial soils although it tolerates low soil fertility and can produce higher yields than Asian rice on alkaline and phosphorus-deficient soils. Floating rice is planted on loam or clay soils.
Conservation
Widespread in cultivation.
[KSP]

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/177112/1467230

Conservation
LC - least concern
[IUCN]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Adapting Agriculture to Climate Change Project, 2015. Ghana Crop Wild Relatives Seed Collecting Guide. Compiled by Ruth Harker & Laura Jennings, RBG Kew

Habit
habit annuals, culms erect, or ascending, 90-150 cm long
Ecology
grown in a wide range of conditions from uplands to mangroves. there are two main ecotypes one is floating and photosenstitive, the other is grown in uplands or moderately dry lowlands. altitude0-1700
Conservation
near endangered.
Distribution
tropical west and central africa
[SCG]

Uses

Use
Food, medicine, livestock feed, ritual.
[KSP]

Common Names

English
Africa Rice, African rice

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
  • GrassBase - The Online World Grass Flora

    • Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora.
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • IUCN Categories

    • IUCN Red List of Threatened Species
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Living Collection Database

    • Common Names from Plants and People Africa http://www.plantsandpeopleafrica.com/
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Species Profiles

    • Kew Species Profiles
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Seed Collection Guides

    • Kew Bulletin
    • http://creativecommons.org/licenses/by-nc-sa/3.0