Cyperus esculentus

Cyperus esculentus is an annual or perennial plant, growing to tall, with solitary stems growing from a tuber. The plant is reproduced by seeds, creeping rhizomes, and tubers. Due to its clonal nature, C. esculentus can take advantage of soil disturbances caused by anthropogenic or natural forces. The stems are triangular in section and bear slender leaves wide. The spikelets of the plant are distinctive, with a cluster of flat, oval seeds surrounded by four hanging, leaf-like bracts positioned 90 degrees from each other. They are long and linear to narrowly elliptic with pointed tips and 8 to 35 florets. The color varies from straw-colored to gold-brown. They can produce up to 2420 seeds per plant. The plant foliage is very tough and fibrous and is often mistaken for a grass. The roots are an extensive and complex system of fine, fibrous roots and scaly rhizomes with small, hard, spherical tubers and basal bulbs attached. The tubers are in diameter and the colors vary between yellow, brown, and black. One plant can produce several hundred to several thousand tubers during a single growing season. With cool temperatures, the foliage, roots, rhizomes, and basal bulbs die, but the tubers survive and resprout the following spring when soil temperatures remain above . When the tubers germinate, many rhizomes are initiated and end in a basal bulb near the soil surface. These basal bulbs initiate the stems and leaves above ground, and fibrous roots underground. C. esculentus is wind pollinated and requires cross pollination as it is self–incompatible. Similar species • Sedges (Cyperus) have grass-like leaves and resemble each other in the appearance. They can mainly be distinguished from grasses by their triangular stems. • Purple nutsedge (C. rotundus) is another weedy sedge that is similar to the yellow nutsedge (C. esculentus). These two sedges are difficult to distinguish from each other and can be found growing on the same site. Some differences are the purple spikelets and the tubers formed by C. rotundus are often multiple instead of just one at the tip. In addition the tubers have a bitter taste instead of the mild almond-like flavour of C. esculentus. ==Ecology==

Cyperus esculentus is a highly invasive species in Oceania, Mexico, some regions of the United States (where it is native), and the Caribbean, mainly by seed dispersion. and Diploschizia impigritella (yellow nut-sedge moth) in North America. Cyperus esculentus likely reached the New World through ocean currents before the Holocene. ==Cultivation==

Cyperus esculentus is cultivated in Egypt, Spain, Nigeria, the United States, Guatemala, Mexico, Chile, Brazil, Lebanon, Syria, Jordan, Saudi Arabia, Oman, Iran, Iraq, Pakistan, India, Yemen, Morocco, Ivory Coast, Sudan, South Sudan, Gambia, Guinea Bissau, Ghana, Niger, Burkina Faso, Togo, Benin, Cameroon, and Mali, where they are used primarily as animal feed or as a side dish, but in Hispanic countries they are used mainly to make horchata, a sweet, milk-like beverage., file by the Valencian Museum of Ethnology Climate requirements Cyperus esculentus cultivation requires a mild climate. Low temperature, shade, and light intensity can inhibit flowering. They do not tolerate salinity. They are planted between April and May and must be irrigated every week until they are harvested in November and December. Tubers develop about 6–8 weeks after seedling emergence and grow quickly during July and August. The maturing is around 90–110 days. The average yield can approach between 10 and 19 t/ha. Compatibility with other crops Cyperus esculentus is extremely difficult to remove completely once established. This is due to the plant having a stratified and layered root system, with tubers and roots being interconnected to a depth of 36 cm or more. The temperatures and humidity levels have to be monitored very carefully during this period. The tiger nuts have to be turned every day to ensure uniform drying. The drying process ensures a longer shelf life. This prevents rot or other bacterial infections, securing quality and high nutrition levels. Disadvantages in the drying process are shrinkage, skin wrinkles and hard nut texture. Storage Tiger nut loses a considerable amount of water during drying and storage. The starch content of the tiger nut tubers decreases and the reducing sugar (invert sugar) content increases during storage. Tiger nut can be stored dry and rehydrated by soaking without losing the crisp texture. Soaking is often done overnight. Dried tiger nuts have a hard texture and soaking is required to render them more easily edible and to ensure acceptable sensory quality. the nutritional composition/100 ml of the Spanish beverage horchata de chufas is as follows: energy content around 66 kcal, proteins around 0.5 g, carbohydrates over 10 g with starch at least 1.9 g, fats at least 2 g. ==Uses==

Dried tiger nut has a smooth, tender, sweet, and nutty taste. It can be consumed raw, roasted, dried, baked or as tiger nut milk, tiger nut drink or oil. Drink In Spain, the drink now known as horchata de chufa (also sometimes called horchata de chufas or, in West African countries such as Nigeria and Mali, kunun aya) is the original form of horchata. It is made from soaked, ground and sweetened tiger nuts mixed with sugar and water. It remains popular in Spain, where a regulating council exists to ensure the quality and traceability of the product in relation to the designation of origin. There it is served ice-cold as a natural refreshment in the summer, often served with fartons. The majority of the Spanish tiger nut crop is utilised in the production of horchata de chufa. Alboraya is the most important production centre. The tubers can be roasted and ground into a coffee substitute. Food , Burkina Faso. The tubers are edible raw or cooked. They have a slightly sweet, nutty flavour, compared to the more bitter-tasting tuber of the related Cyperus rotundus (purple nutsedge). They are quite hard and are generally soaked in water before they can be eaten, making them much softer and giving them a better texture. They are a popular snack in West Africa. The tubers can also be dried and ground into flour. Its popularity was depicted in movies, such as the song named after it, "Ḥab el ʿAzīz". Flour of roasted tiger nut is sometimes added to biscuits and other bakery products as well as in making oil, soap, and starch extracts. It is also used for the production of nougat, jam, beer, and as a flavoring agent in ice cream and in the preparation of kunu (a local beverage in Nigeria). Kunu is a nonalcoholic beverage prepared mainly from cereals (such as millet or sorghum) by heating and mixing with spices (dandelion, alligator pepper, ginger, licorice) and sugar. To make up for the poor nutritional value of kunu prepared from cereals, tiger nut was found to be a good substitute for cereal grains. Tiger nut oil can be used naturally with salads or for deep frying. It is considered to be a high-quality oil. Tiger nut "milk" has been tried as an alternative source of milk in fermented products, such as yogurt production, and other fermented products common in some African countries and can thus be useful replacing milk in the diet of people intolerant to lactose to a certain extent. A similar 6-year study found tuber yields ranging from 4.02 to 6.75 t/ha, with an average oil content of 26.5% and an average oil yield of 1.47 t/ha. The oil of the tuber was found to contain 18% saturated (palmitic acid and stearic acid) and 82% unsaturated (oleic acid and linoleic acid) fatty acids. Fishing bait The boiled nuts are used in the UK as a bait for carp. The nuts have to be prepared in a prescribed manner to prevent harm to the fish. The nuts are soaked in water for 24 hours, and then boiled for 20 minutes or longer until fully expanded. Some anglers then leave the boiled nuts to ferment for 24–48 hours, which can enhance their effectiveness. If the nuts are not properly prepared, they can be toxic to carp. This was originally thought to have been the cause of death of Benson, a large, well-known female carp weighing found floating dead in a fishing lake, with a bag of unprepared tiger nuts lying nearby, empty, on the bank. An examination of the fish by a taxidermist concluded tiger nut poisoning was not the cause of death, but rather the fish had died naturally. History It has been suggested that the extinct hominin Paranthropus boisei (the "Nutcracker Man") subsisted on tiger nuts. Cyperus esculentus was one of the oldest cultivated plants in prehistoric and Ancient Egypt, where it was an important food. Roots of wild chufa have been found at Wadi Kubbaniya, north of Aswan, dating to around 16,000 BC. Dry tubers also appear later in tombs of the Predynastic period, around 3000 BC. During that time, C. esculentus tubers were consumed either boiled in beer, roasted, or as sweets made of ground tubers with honey. The tubers were also used medicinally, taken orally, as an ointment, or as an enema, and used in fumigants to sweeten the smell of homes or clothing. Chufa continued to be an important source of food in the Dynastic period, and cultivation of the plant remained exclusively in Egypt. The tomb of the vizier Rekhmire from the 15th century BCE, shows peasants preparing and measuring tiger nuts to make votive cakes as offerings to the god Amun. The modern name for tiger nuts in Egypt is حب العزيز (ḥab el ʿAzīz = grains of Al-Aziz) named after the Fatimid ruler who was reputedly fond of it. == Gallery ==

File:Cyperus esculentis in a lawn.jpg File:Cyperus esculentus 6801.JPG File:Cyperus esculentus.jpg File:Cyperus ¿ esculentus ? (3825833254).jpg == References ==