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 leaves positioned 90 degrees from each other. The plant foliage is very tough and fibrous, and is often mistaken for a grass.

Cultivation and uses
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. They have various uses; in particular, they are used in Spain to make horchata. They are sometimes known by their Spanish name, "chufa". 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." 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.

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.

According to the Consejo Regulador de Chufa de Valencia (Regulating Council for Valencia's Tigernuts), 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.

It can replace milk in the diet of people intolerant to lactose.

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

It is extremely difficult to remove permanently when it is considered to be an intrusive weed in lawns and gardens. This is due to the plant having a stratified and layered root system, with tubers and roots being interconnected to each other to a depth of 50 cm or more. The tubers are connected by fragile roots that are extremely prone to snapping when pulled on, making the plant extremely difficult to remove with its entire root system intact, and the plant can quickly regenerate if even a single tuber is left in place. Repeated applications of Gordon's Trimec Plus have proven effective in eliminating this weed from lawns.

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. sativa. Asia, cultivated origin.