Prota 1: Cereals and pulses/Céréales et légumes secs
Fl. ind. 1: 238 (1820).
n = 15, 16, 17, 18, 24
Cram-cram, Indian sandbur (En). Cram-cram (Fr).
Origin and geographic distribution
Cenchrus biflorus is found throughout tropical Africa, extending eastwards through Arabia and Iran to Pakistan and India. It has been introduced elsewhere, e.g. in North America and Australia.
The grain of Cenchrus biflorus is edible and highly nutritious. People in areas of marginal subsistence regularly collect the seed; elsewhere it is considered a famine food. In the Sahel it is collected as a wild cereal, e.g. by the Tuareg people. The grains are pounded and eaten raw, made into porridge, or mixed and cooked with other foods. The grain is also made into a drink. In Sudan a thin bread (‘kisra’) is made from the grain and in Mauritania the ground grains are made into cakes. The grain of Cenchrus biflorus is also a famine food in India, where it is eaten raw or used, mixed with pearl millet, to make bread. In normal years it is mixed with sugar and ‘ghee’, and eaten as a children’s food.
Cenchrus biflorus is considered a valuable forage grass in the Sahel; it is mainly browsed in the juvenile stage and when the grains have fallen off. It can be cut several times during the rainy season and made into hay or silage. The spiny involucres are sufficiently softened by ensiling to make consumption of the whole plant possible. Cenchrus biflorus persists until the end of the dry season and thus is important as a reliable source of fodder. Also in India the plant is used as a fodder and it is sown against desertification; in northern Australia it is sown as a forage. The leaves are eaten during famine in the Thar desert in India.
The root of Cenchrus biflorus is an ingredient of traditional aphrodisiac prescriptions.
The composition of hulled grains of Cenchrus biflorus per 100 g is: water 9.8 g, energy 1549 kJ (370 kcal), protein 17.8 g, fat 8.5 g, carbohydrate 62.3 g, Ca 144 mg, P 270 mg and Fe 22 mg (Leung, Busson & Jardin, 1968). The essential amino-acid composition per 100 g hulled grain is: lysine 214 mg, methionine 393 mg, phenylalanine 926 mg, threonine 658 mg, valine 1052 mg, leucine 2745 mg and isoleucine 892 mg (FAO, 1970). The protein and fat contents are high compared to other cereals.
Cenchrus biflorus plants in the Sahel contain crude protein 10.0%, crude fibre 34.6%, crude fat 1.5%, nitrogen-free extracts 42.8%, P 0.35%, K 4.18%, Ca 0.28%, Mg 0.21% and Na 0.01%.
In spite of its usefulness, Cenchrus biflorus is often considered a noxious weed; the spiny inflorescences may injure humans and livestock and cause infection.
Loosely tufted, annual grass, with ascending stems (culms) up to 1 m tall. Leaves alternate, simple and entire; ligule a line of hairs; blade linear, flat, 2–25(–35) cm × 2–7(–10) mm, apex filiform. Inflorescence a spike-like panicle 2–15 cm × 9–12 mm, with 1–3 spikelets enclosed by an involucre of prickly bristles; rachis angular, sinuous; involucre ovoid, 4–11 mm long with numerous spines, inner spines erect, fused at base, retrorsely hairy on the pungent, recurving apex, outer spines shorter, spreading. Spikelet lanceolate 3.5–6 mm long, acute, consisting of 2 glumes and usually 2 florets; glumes shorter than spikelet; lower floret male or sterile, its lemma as long as spikelet, membranous, upper floret bisexual, its lemma as long as spikelet, thinly leathery; stamens 3, ovary superior, glabrous, with 2 hairy stigmas. Fruit a dorsally compressed caryopsis (grain), 2–2.5 mm × 1.5–2 mm.
Cenchrus comprises about 20 species in tropical and warm temperate regions, mainly in Africa and the Americas. It is closely related to Pennisetum, which differs in non-spiny inner involucral bristles free to the base.
The spiny spikelets of Cenchrus biflorus adhere to hairs of animals and clothes, making possible wide dispersal. Cenchrus biflorus follows the C4>-cycle photosynthetic pathway.
Cenchrus biflorus is mostly found in semi-arid and arid regions with an annual rainfall of 250–650 mm, up to 1300 m altitude, usually on dry sandy soils and in cultivated, overgrazed or otherwise disturbed areas. It is extremely abundant in the Sahel and southern Sahara, where it may form massive stands. A study in western Niger showed that it had become much more abundant and dominant in the late 1980s than it was in the early 1960s.
Cenchrus biflorus can be propagated by seed. The optimum temperature for seed germination is 35°C. In tropical Africa the grains are collected from the wild. The spiny spikelets shatter easily at maturity and are often allowed to fall, after which they are swept into piles with a bunch of straw, or they are raked with a big ‘comb’ with a handle. The plants may be beaten with a stick if not all spikelets have fallen. The spikelets are pounded in a mortar and the grains are separated by winnowing. In the Lake Chad area the inflorescences are cut off with a knife, after which the grains are dried, threshed and winnowed. In Kordofan (Sudan) the grains are hulled by rubbing them between two pieces of leather.
Genetic resources and breeding
The International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, holds 10 accessions of Cenchrus biflorus. In view of its wide distribution and abundance, Cenchrus biflorus is certainly not threatened by genetic erosion.
Cenchrus biflorus yields a highly nutritious grain, with unusually high protein and fat contents. Formerly it was important as a wild cereal, but nowadays it seems to play a role in human nutrition in times of shortage only. As a forage it has remained important, especially because of its persistence throughout the dry season. Cenchrus biflorus is unlikely to become more important in the future, mainly due to its spiny spikelets which adhere to clothes and cause injuries to humans and animals, and result in the plant often being considered a noxious weed.
• Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families E–I. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp.
• Clayton, W.D. & Renvoize, S.A., 1982. Gramineae (Part 3). In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. pp. 451–898.
• Naegele, A.F.G., 1977. Plantes fourragères spontanées d’Afrique tropicale seche: données techniques. Aménagement écologique des pâturages arides et semi arides d’Afrique, du Proche et du Moyen Orient (EMASAR phase 2). Volume 3. FAO, Rome, Italy. 510 pp.
• National Research Council, 1996. Lost crops of Africa. Volume 1: grains. National Academy Press, Washington D.C., United States. 383 pp.
• Phillips, S., 1995. Poaceae (Gramineae). In: Hedberg, I. & Edwards, S. (Editors). Flora of Ethiopia and Eritrea. Volume 7. Poaceae (Gramineae). The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. 420 pp.
• Bartha, R., 1970. Fodder plants in the Sahel zone of Africa. Weltforum Verlag, München, Germany. 306 pp.
• Batello, C., Marzot, M. & Touré, A.H., 2004. The future is an ancient lake: traditional knowledge, biodiversity and genetic resources for food and agriculture in Lake Chad Basin ecosystems. FAO, Rome, Italy. 307 pp.
• Bhandari, M.M., 1974. Famine foods in the Rajasthan desert. Economic Botany 28: 73–81.
• Bouwman, L., 1979. Een onderzoek naar de groei en ontwikkeling van de Sahel grassen: Pennisetum pedicellatum, Eragrostis tremula, Loudetia togoensis, Cenchrus biflorus, aangevuld met: Aristida mutabilis, Cassia tora, Zornia glochidiata. Doctoraalverslag Rijksuniversiteit Utrecht. Centrum voor Agrobiologisch Onderzoek (CABO), Wageningen, Netherlands. 91 pp.
• Clayton, W.D., 1989. Gramineae (Paniceae, Isachneae and Arundinelleae). In: Launert, E. & Pope, G.V. (Editors). Flora Zambesiaca. Volume 10, part 3. Flora Zambesiaca Managing Committee, London, United Kingdom. 231 pp.
• Cope, T.A., 1995. Poaceae (Gramineae). In: Thulin, M. (Editor). Flora of Somalia. Volume 4. Angiospermae (Hydrocharitaceae-Pandanaceae). Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 148–270.
• FAO, 1970. Amino-acid content of foods and biological data on proteins. FAO Nutrition Studies No 24, Rome, Italy. 285 pp.
• Harlan, J.R., 1989. Wild grass seed harvesting in the Sahara and sub Sahara of Africa. In: Harris, D.R. & Hillman, G.C. (Editors). Foraging and farming: the evolution of plant exploitation. Unwin Hyman, London, United Kingdom. pp. 79–98.
• Leung, W.-T.W., Busson, F. & Jardin, C., 1968. Food composition table for use in Africa. FAO, Rome, Italy. 306 pp.
• Peyre de Fabrègues, B., 1992. Observations on the ebb and flow of native grasses in the area of the Ekrafane Ranch, Sahel. In: Chapman, G.P. (Editor). Desertified grasslands: their biology and management. Papers presented at an international symposium organized by the Linnean Society of London and Wye College, University of London, held at the Linnean Society’s Rooms, London, 27, 28 February and 1 March 1991. Academic Press, London, United Kingdom. pp. 37–46.
Correct citation of this article:
Brink, M., 2006. Cenchrus biflorus Roxb. In: Brink, M. & Belay, G. (Editors). PROTA 1: Cereals and pulses/Céréales et légumes secs. [CD-Rom]. PROTA, Wageningen, Netherlands.