Cyperus esculentus

Cyperus esculentus
Scientific classification
Kingdom: Plantae (unranked): Angiosperms (unranked): Monocots (unranked): Commelinids Order: Poales Family: Cyperaceae Genus: Cyperus Species: C. esculentus
Binomial name
Cyperus esculentus L.

Cyperus esculentus (Chufa Sedge, Yellow Nutsedge, Tigernut Sedge, Earthalmond) is a species of sedge native to warm temperate to subtropical regions of the Northern Hemisphere. It is an annual or perennial plant, growing to 90 cm tall, with solitary stems growing from a tuber. The stems are triangular in section, and bear slender leaves 3-10 mm wide. The flowers 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. The plant foliage is very tough and fibrous, and is often mistaken for a grass.

There are several varieties:

• Cyperus esculentus var. esculentus. Mediterranean region east to India.
• Cyperus esculentus var. hermannii. Florida.
• Cyperus esculentus var. leptostachyus. United States.
• Cyperus esculentus var. macrostachyus. United States.
• Cyperus esculentus var. sativus. Asia, cultivated origin.

Cultivation and uses

History

Zohary and Hopf consider this tuber "ranks among the oldest cultivated plants in Ancient Egypt." Although noting that "Chufa was no doubt an important food element in ancient Egypt during dynastic times, its cultivation in ancient times seems to have remained (totally or almost totally) an Egyptian specialty."^[1] They were used to make cakes in ancient Egypt. Presently, they are cultivated mainly, at least for extended and common commercial purposes, in Spain, where they were introduced by Arabs, almost exclusively in the Valencia region. They are found extensively in California and were grown by the Paiute in Owens Valley.

Tiger nuts are also grown in Ghana, Nigeria, Burkina Faso and Mali.

Use as food

The tubers are edible, with 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, thus making them much softer and giving them a better texture. They have various uses; in particular, they are used in Spain to make horchata. They are sometimes known by their Spanish name, "chufa".

Tigernuts have excellent nutritional qualities with a fat composition similar to olives and a rich mineral content, especially phosphorus and potassium. Tigernuts are also gluten- and cholesterol-free, and have a very low sodium content. 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.^[2]

According to the Consejo Regulador de Chufa de Valencia (Regulating Council for Valencia's Tigernuts),^[3] the nutritional composition/100 ml of a classical Horchata de Chufas, or Orxata de Xufes in Valencian language, 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.

Even though too low in proteins and in fats, and too high in carbohydrates, to be considered equal to milk, Horchata de Chufas can be useful in somehow replacing milk in the diet of people intolerant to lactose.

Use as oil

Since the tubers contain 20-36% oil, C. esculentus has been suggested as potential oil crop for the production of biodiesel. ^[2]

Use as fishing bait

The boiled nuts are used in the UK as a bait for carp and have a high reputation for success. The nuts have to be prepared in a prescribed manner in order to prevent harm to the fish. The nuts are soaked in water for 24hrs and then boiled for 20 minutes or longer until fully expanded. Some anglers then leave the boiled nuts to ferment for 24-48 hrs which can enhance their effectiveness further.

Removal

It is extremely difficult to remove completely from lawns and gardens where it is considered an intrusive weed. This is due to the plant having a stratified and layered root system, with tubers and roots being interconnected to a depth of 50 cm or more^{[citation needed]}. The tubers are connected by fragile roots that are prone to snapping when pulled, making the root system difficult to remove intact. The plant can quickly regenerate if a single tuber is left in place.

Wikibooks' A Wikimanual of Gardening has more about this subject: Cyperus esculentus

Nutsedge can be killed by repeated use of Roundup brand weed killer (glyphosate). Spray the nutsedge. It will die back and then re-sprout. Repeat the spray as soon as there is some green foliage. Keep repeating until it does not come back.^{[citation needed]}

Notes

1. ^ Daniel Zohary and Maria Hopf, Domestication of plants in the Old World, third edition (Oxford: University Press, 2000), p. 198
2. ^ ^{a b} Zhang et al Yellow nut-sedge tuber oil as a fuel [1]
3. ^ Consejo Regulador de Chufa de Valencia [2]