||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (July 2012)|
Cyperus papyrus (papyrus sedge, paper reed, Indian matting plant, Nile grass) is a species of aquatic flowering plant belonging to the sedge family Cyperaceae. It is a tender herbaceous perennial, native to Africa, and forms tall stands of reed-like swamp vegetation in shallow water.
Papyrus sedge (and its close relatives) has a very long history of use by humans, notably by the Ancient Egyptians—it is the source of papyrus paper, parts of it can be eaten, and the highly buoyant stems can be made into boats. It is now often cultivated as an ornamental plant.
In nature it grows in full sun, in flooded swamps and on lake margins throughout Africa, Madagascar and the Mediterranean countries. 
This tall, robust, leafless aquatic plant can grow 4 to 5 m (13 to 16 ft) high. It forms a grass-like clump of triangular green stems that rise up from thick, woody rhizomes. Each stem is topped by a dense cluster of thin, bright green, thread-like stems around 10 to 30 cm (4 to 10 in) in length, resembling a feather duster when the plant is young. Greenish-brown flower clusters eventually appear at the ends of the rays, giving way to brown, nut-like fruits.
The younger parts of the rhizome are covered by red-brown, papery, triangular scales, which also cover the base of the culms. Botanically these represent reduced leaves, so strictly it is not quite correct to call this plant fully "leafless".
Papyrus in history
Egyptians used the plant for many purposes, most famously for making papyrus paper. Its name in Greek and in English is widely believed to have come from Egyptian. Cyperus papyrus is now used mainly for decoration, as it is nearly extinct in its native habitat in the Nile Delta, where in ancient times it was widely cultivated. Theophrastus' "History of Plants" (Book iv. 10) states that it grew in Syria; and, according to Pliny's Natural History, it was also a native plant of the Niger River and the Euphrates.
Aside from papyrus, several other members of the genus Cyperus may actually have been involved in the multiple uses Egyptians found for the plant. Its flowering heads were linked to make garlands for the gods in gratitude. The pith of young shoots was eaten both cooked and raw. Its woody root made bowls and other utensils and was burned for fuel. From the stems were made reed boats (seen in bas-reliefs of the Fourth Dynasty showing men cutting papyrus to build a boat; similar boats are still made in southern Sudan), sails, mats, cloth, cordage, and sandals. Theophrastus states that King Antigonus made the rigging of his fleet of papyrus, an old practice illustrated by the ship's cable, wherewith the doors were fastened when Odysseus slew the suitors in his hall (Odyssey xxi. 390).
The adventurer Thor Heyerdahl built two boats from papyrus, Ra and Ra II, in an attempt to demonstrate that ancient African or Mediterranean people could have reached America. He succeeded in sailing Ra II from Morocco to Barbados. Fishermen in the Okavango Delta use small sections of the stem as floats for their nets.
Papyrus can be found in tropical rain forests, tolerating annual temperatures of 20 °C (68 °F) to 30 °C (86 °F) and a pH of 6.0 to 8.5. Papyrus flowers in late summer, and prefers full sun to partly shady conditions. Like most tropical plants, it is sensitive to frost. In the United States it has become invasive in Florida and has escaped from cultivation in Louisiana, California and Hawaii.
Papyrus sedge forms vast stands in swamps, shallow lakes, and along stream banks throughout the wetter parts of Africa, but it has become rare in the Nile Delta. In deeper waters it is the chief constituent of the floating, tangled masses of vegetation known as sudd. It also occurs in Madagascar, and some Mediterranean countries such as Sicily and the Levant.
The "feather-duster" flowering heads make ideal nesting sites for many social species of birds. As in most sedges, pollination is by wind, not insects, and the mature fruits after release are distributed by water.
In recent years papyrus has been the subject of intense ecological studies centered around its prodigious growth rate and ability to recycle nutrients. Much of this research was begun at Makerere University in Uganda in the early 1970s in the swamps on the edge of Lake Victoria and continued in Kenya (University of Nairobi) on Lake Naivasha. John Gaudet's work in Africa, supported by a National Geographic Society grant, appeared in various scientific journals over the period 1975-1991. In addition, other pioneer researchers of papyrus at Makerere in the 1970s were: Keith Thompson, T. R. Milburn, and Mike Jones. Thompson's studies of papyrus swamp development throughout Africa (1976–1985) later formed the basis for management and conservation at national levels.
Extensive research on the productive physiology of papyrus were carried out by Jones from the 1980s onward. He started his work in Uganda and later continued his research on Lake Naivasha in Kenya where he was joined by a new generation of African researchers including Frank Muthuri. Jones's latest research (2002) found that papyrus is a C4 sedge that forms highly productive monotypic stands over large areas of wetland in Africa. Jones and others measured eddy covariance from a stand of Cyperus papyrus, which formed a fringing swamp on the north-west shore of Lake Naivasha, Kenya. They determined that fluxes of CO2 and H2O vapor between the papyrus swamp and the atmosphere were large but variable, depending on the hydrology of the wetland system and the condition of the vegetation. These measurements, combined with simulation modeling of annual fluxes of CO2, showed that papyrus swamps have the potential to sequester large amounts of carbon (1.6 kg C m-2 y-1)[clarification needed] when detritus accumulates under water in anaerobic conditions, but they are a net source of carbon release to the atmosphere (1.0 kg C m-2 y-1)[clarification needed] when water levels fall to expose detritus and rhizomes to aerobic conditions. Evapotranspiration from papyrus swamps was frequently lower than evaporation from open water surfaces and plant factors have a strong influence on the flux of water to the atmosphere.
Research on the papyrus swamp habitat has in recent years attracted the attention of many more African biologists, such as A. O. Owino, K. M. Mavuti, S. M. Muchiri and S. Njuguna. Increasingly, the value of papyrus to other species is being recognized. Papyrus swamps provide hypoxic and structural refugia for cichlids from the large predatory Nile Perch and are an important habitat for several endangered bird species.(Chapman et al. 1996; 2003; Maclean et al. 2003a; 2006).
The late 1990s also saw the rise in research on the papyrus swamps of Lake Naivasha in Kenya by teams from the English Universities of Leicester and East Anglia, notably led by David M. Harper. Harper's extensive recent studies on the swamps and lakes have led to a worldwide awareness of the problems facing papyrus swamps in Africa today.
The papyrus plant is relatively easy to grow from seed, though in Egypt it is more common to split the rootstock, and grows quite fast once established. Plant the seeds close to the surface in moist planting soil mixed with peat and sand (ratio 2:1:1). Keep the soil moist and at a temperature of 25 to 28 °C, the seeds will grow in 25 to 30 days. Once they have grown keep the soil very wet at all times and place them in a sunny location.
- "Cyperus papyrus". plantzafrica.com.
- "Cyperus papyrus AGM". Royal Horticultural Society. Retrieved 2012-10-16.
- "Cyperus papyrus 'Nanus' AGM". Royal Horticultural Society. Retrieved 2012-10-16.
- "Cyperus papyrus L.". Purdue University. Retrieved December 30, 2014.
- "Cyperus papyrus" (in Swedish). Impecta. Retrieved December 30, 2014.
- Boar, R. R., D. M. Harper and C. S. Adams. 1999. Biomass Allocation in Cyperus papyrus in a Tropical Wetland, Lake Naivasha, Kenya. 1999. Biotropica 3: 411.
- Chapman, L.J., C.A. Chapman, R. Ogutu-Ohwayo, M. Chandler, L. Kaufman and A.E. Keiter. 1996. Refugia for endangered fishes from an introduced predator in Lake Nabugabo, Uganda. Conservation Biology 10: 554-561.
- Chapman, L.J., C.A. Chapman, P.J. Schofield, J.P. Olowo, L. Kaufman, O. Seehausen and R. Ogutu-Ohwayo. 2003. Fish faunal resurgence in Lake Nabugabo, East Africa. Conservation Biology 17: 500-511.
- Gaudet, John. 1975. Mineral concentrations in papyrus in various African swamps. Journal of Ecology 63: 483-491.
- Gaudet, John. 1976. Nutrient relationships in the detritus of a tropical swamp.Archiv fur Hydrobiologie 78: 213-239.
- Gaudet, John. 1977. Natural drawdown on Lake Naivasha, Kenya and the formation of papyrus swamps. Aquatic Botany 3: 1-47.
- Gaudet, John. 1977. Uptake and loss of mineral nutrients by papyrus in tropical swamps. Ecology 58: 415-422.
- Gaudet, John. 1978. Effect of a tropical swamp on water quality. Verh. Internat. Ver. Limnol. 20: 2202-2206.
- Gaudet, John. 1978. Seasonal changes in nutrients in a tropical swamp. Journal of Ecology 67: 953-981.
- Gaudet, John. 1980. Papyrus and the ecology of Lake Naivasha. National Geographic Society Research Reports. 12: 267-272.
- Gaudet, J. and J. Melack. 1981. Major ion chemistry in a tropical African lake basin. Freshwater Biology 11: 309-333.
- Gaudet, J. and C. Howard-Williams. 1985. “The structure and functioning of African swamps.” In (ed. Denny) The Ecology and Management of African Wetland Vegetation. Dr.w.Junk, Pub., Dordrecht (pp. 154–175).
- Gaudet, John. 1991. Structure and function of African floodplains. Journal of the East African Natural Historical Society. 82(199): 1-32.
- Harper, D.M., K.M. Mavuti and S. M. Muchiri. 1990: Ecology and management of Lake Naivasha, Kenya, in relation to climatic change, alien species introductions and agricultural development. Environmental Conservation 17: 328–336.
- Harper, D. 1992. The ecological relationships of aquatic plants at Lake Naivasha, Kenya. Hydrobiologia. 232: 65-71.
- Howard-Williams, C. and K. Thompson. 1985. The conservation and management of African wetlands. In (ed. Denny) The Ecology and Management of African Wetland Vegetation. Dr.w.Junk, Pub., Dordrecht (pp. 203–230).
- Jones, M.B. and T. R. Milburn. 1978. Photosynthesis in Papyrus (Cyperus papyrus L.), Photosynthetica. 12: 197 - 199.
- Jones, M. B. and F. M. Muthuri. 1997. Standing biomass and carbon distribution in a papyrus (Cyperus Papyrus L) swamp on Lake Naivasha, Kenya. Journal of Tropical Ecology. 13: 347–356.
- Jones M.B. and S. W. Humphries. 2002. Impacts of the C4 sedge Cyperus papyrus L. on carbon and water fluxes in an African wetland. Hydrobiologia, Volume 488, pp. 107–113.
- Maclean, I.M.D. 2004. An ecological and socio-economic analysis of biodiversity conservation in East African wetlands. Unpublished PhD thesis, University of East Anglia, Norwich.
- Maclean, I.M.D., M. Hassall, M. R. Boar and I. Lake. 2006. Effects of disturbance and habitat loss on papyrus-dwelling passerines. Biological Conservation., 131: 349-358.
- Maclean, I.M.D., M. Hassall, R. Boar, R. and O. Nasirwa. 2003a. Effects of habitat degradation on avian guilds in East African papyrus Cyperus papyrus L. swamps. Bird Conservation International, 13: 283-297.
- Maclean, I.M.D., R. Tinch, M. Hassall and R.R. Boar, R.R. 2003b. Social and economic use of wetland resources: a case study from Lake Bunyonyi, Uganda. Environmental Change and Management Working Paper No. 2003-09, Centre for Social and Economic Research into the Global Environment, University of East Anglia, Norwich.
- Maclean, I.M.D., R. Tinch, M. Hassall and R.R. Boar. 2003c. Towards optimal use of tropical wetlands: an economic evaluation of goods derived from papyrus swamps in southwest Uganda. Environmental Change and Management Working Paper No. 2003-10, Centre for Social and Economic Research into the Global Environment, University of East Anglia, Norwich.
- Messenger Dally. 1908 How papyrus defeated South Sydney and assisted in making Eastern Suburbs great
- Muthuri, F. M., M. B. Jones, and S.K. Imbamba. 1989. Primary productivity of papyrus (Cyperus papyrus) in a tropical swamp - Lake Naivasha, Kenya, Biomass, 18: 1 - 14.
- Muthuri, F. M. and M. B. Jones. 1997. Nutrient distribution in a papyrus swamp: Lake Naivasha, Kenya. Aquatic Botany, 56: 35–50.
- Owino, A. O. and P. G. Ryan. 2006. Habitat associations of papyrus specialist birds at three papyrus swamps in western Kenya. African Journal of Ecology 44: 438-443.
- Thompson, K. 1976. Swamp development in the head waters of the White Nile. In (ed.J. Rzoska) ‘‘The Nile. Biology of an Ancient River.’’Monographiae Biologicae, 29. Dr.W. Junk b.v., The Hague.
- Thompson, K., P.R. Shewry & H.W. Woolhouse. 1979. Papyrus swamp development in the Upemba Basin, Zaire: Studies of population structure in Cyperus papyrus stands. Botanical Journal of the Linn. Soc. 78: 299-316.
|Wikimedia Commons has media related to Cyperus papyrus.|
- Purdue University: Cyperus papyrus factsheet
- University of Connecticut Ecology & Evolutionary Biology Conservatory
- Dressler, S.; Schmidt, M. & Zizka, G. (2014). "Cyperus papyrus ". African plants – a Photo Guide. Frankfurt/Main: Forschungsinstitut Senckenberg.