Prota 1: Cereals and pulses/Cιrιales et lιgumes secs
Bull. Mus. natn. Hist. nat., Paris 16: 405 (1911).
2n = 24
Oryza breviligulata A.Chev. & Roehr. (1914), Oryza stapfii Roshev. (1931).
Wild rice, self-sown rice, Mandinka rice (En). Riz sauvage annuel, riz de marais, riz sauvage (Fr).
Origin and geographic distribution
Oryza barthii is distributed in tropical Africa from Mauritania east to Ethiopia and south to Botswana and Zimbabwe.
The grains of Oryza barthii are sometimes collected if enough plants are available, and they serve as a famine food. They are sometimes sold in markets. However, Oryza barthii is regarded mostly as a weed. Before flowering the plant provides good grazing for livestock; after flowering the awns may cause injury to the mouth.
The grain of Oryza barthii has a good flavour.
Annual grass up to 150 cm tall, growing in tufts; stem (culm) erect or geniculately ascending, with roots from the lower nodes, spongy, striate, glabrous. Leaves alternate, simple and entire; leaf sheath striate, smooth; ligule 26(9) mm long, truncate or rounded; blade linear, 1545 cm Χ 0.51.5 cm, with acute apex, intense green, glabrous, smooth on the lower surface, slightly rough on the upper surface. Inflorescence a terminal panicle 2035 cm Χ 37.5 cm, rather dense, erect or more rarely somewhat nodding, with erect or obliquely ascending branches. Spikelet oblong to narrowly oblong, 711 mm long (awn excluded), deciduous, pale green to straw-coloured, 3-flowered but 2 lowest florets reduced to sterile lemmas 2.54.5 mm long; glumes reduced to a 2-lobed rim; lemma of fertile floret slightly shorter than spikelet, boat-shaped, leathery, hairy, with 2 longitudinal lateral grooves, with pink to purplish stiff awn (4)816(19) cm long; palea about as long as lemma but much narrower, with the apex drawn out in a short blunt point; lodicules 2; stamens 6; ovary superior, with 2 plumose stigmas. Fruit a caryopsis (grain).
Oryza comprises about 20 wild species distributed throughout the tropics and subtropics, and 2 cultivated species, Oryza sativa L. and Oryza glaberrima Steud. Oryza barthii is classified in ser. Sativae, together with Oryza sativa, Oryza glaberrima and Oryza longistaminata A.Chev. & Roehr.
Oryza barthii is predominantly inbreeding, with an outcrossing rate of 520%.
Oryza barthii grows in shallow water in ponds and marshes, and as a weed in rice fields, up to 1500 m altitude. It may form pure stands, but is usually found scattered with other aquatic grasses. It may become a noxious weed and may act as a reservoir for important rice diseases and pests. Oryza barthii is a short-day plant.
Oryza barthii is not normally cultivated, but the grain is collected from the wild. The grain shatters very easily, and the panicles are usually collected before they are mature. If ripe, the panicles are harvested over a basket or calabash to collect falling grain.
Genetic resources and breeding
Oryza barthii has a relatively narrow genetic variation. It is considered a source of resistance to various diseases affecting Oryza sativa, including bacterial leaf blight (Xanthomonas oryzae pv. oryzae), rice yellow mottle virus (RYMV) and sheath blight (Thanatephorus cucumeris, anamorph: Rhizoctonia solani).
Although Oryza barthii may serve as a famine food during times of shortage, it is probably more often considered a weed of Oryza sativa than a valuable food plant, and there seems to be no reason to justify its promotion. The greatest potential of Oryza barthii is probably as a source of resistance to various diseases affecting Oryza sativa.
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Correct citation of this article:
Brink, M., 2006. Oryza barthii A.Chev. In: Brink, M. & Belay, G. (Editors). PROTA 1: Cereals and pulses/Cιrιales et lιgumes secs. [CD-Rom]. PROTA, Wageningen, Netherlands.
field of flowering plants