Coco grass, Java grass, Cyperus rotundus

Cyperus rotundus (coco-grass, Java grass, nut grass, purple nut sedge or purple nutsedge, red nut sedge, Khmer kravanh chruk) is a species of sedge (Cyperaceae) native to Africa, southern and central Europe (north to France and Austria), and southern Asia. The word cyperus derives from the Greek κύπερος, kyperos, and rotundus is from Latin, meaning "round". The earliest attested form of the word cyperus is the Mycenaean Greek 𐀓𐀞𐀫, ku-pa-ro.
Cyperus rotundus is a perennial plant, that may reach a height of up to 140 cm (55 in). The names "nut grass" and "nut sedge" – shared with the related species Cyperus esculentus – are derived from its tubers, that somewhat resemble nuts, although botanically they have nothing to do with nuts.
As in other Cyperaceae, the leaves sprout in ranks of three from the base of the plant, around 5–20 cm (2–8 in) long. The flower stems have a triangular cross-section. The flower is bisexual and has three stamina and a three-stigma carpel, with the flower head having three to eight unequal rays. The fruit is a three-angled achene.
The root system of a young plant initially forms white, fleshy rhizomes, up to 25 mm (1.0 in) in dimension, in chains. Some rhizomes grow upward in the soil, then form a bulb-like structure from which new shoots and roots grow, and from the new roots, new rhizomes grow. Other rhizomes grow horizontally or downward, and form dark reddish-brown tubers or chains of tubers.
It prefers dry conditions, but will tolerate moist soils, and often grows in wastelands and in crop fields.C. rotundus has many beneficial uses. It is a staple carbohydrate in tropical regions for recent hunter-gatherers and is a famine food in some agrarian cultures.
Folk medicine
In traditional Chinese medicine, C. rotundus is considered the primary qi-regulating herb.
The plant is mentioned in the ancient Indian ayurvedic medicine Charaka Samhita (circa 100 AD). Modern ayurvedic medicine uses the plant, known as musta or musta moola churna, for fevers, digestive system disorders, dysmenorrhea, and other maladies.
Arabs of the Levant traditionally use roasted tubers, while they are still hot, or hot ashes from burned tubers, for wounds, bruises, and carbuncles.[citation needed] Western and Islamic herbalists including Dioscorides, Galen, Serapion, Paulus Aegineta, Avicenna, Rhazes, and Charles Alston have described its use as a stomachic, emmenagogue, and deobstruent, and in emollient plasters.
The antibacterial properties of the tubers may have helped prevent tooth decay in people who lived in Sudan 2000 years ago. Less than 1% of that local population's teeth had cavities, abscesses, or other signs of tooth decay, though those people were probably farmers (early farmers' teeth typically had more tooth decay than those of hunter-gatherers because the high grain content in their diet created a hospitable environment for bacteria that flourish in the human mouth, excreting acids that eat away at the teeth).
Modern uses and studies
Several chemical substances have been identified in C. rotundus: cadalene, cyprotene, flavonoids, sesquiterpenes, terpenoids, mustakone, isocyperol, acyperone, rotundene, valecine, kaempferol, luteolin, quercetin, patchoulenone, isopatchoulenone, sugeonyl acetate, cellulose triacetate and sugebiol.A sesquiterpene, rotundone, so called because it was originally extracted from the tuber of this plant, is responsible for the spicy aroma of black pepper and the peppery taste of certain Australian Shiraz wines.
Extract from leaves and tubers of Cyperus rotundus L. increase the adventitious rooting of different species. These extracts contain a large amount of auxins and phenolic compounds that promote the rooting of cuttings and seedlings.Sleeping mats
The well dried coco grass is used in mats for sleeping.Cyperus rotundus is one of the most invasive weeds known, having spread out to a worldwide distribution in tropical and temperate regions. It has been called "the world's worst weed" as it is known as a weed in over 90 countries, and infests over 50 crops worldwide. In the United States it occurs from Florida north to New York and Minnesota and west to California and most of the states in between. In the uplands of Cambodia, it is described as an important agricultural weed.
Its existence in a field significantly reduces crop yield, both because it is a tough competitor for ground resources, and because it is allelopathic, the roots releasing substances harmful to other plants. Similarly, it also has a bad effect on ornamental gardening. The difficulty to control it is a result of its intensive system of underground tubers, and its resistance to most herbicides. It is also one of the few weeds that cannot be stopped with plastic mulch.Weed pulling in gardens usually results in breakage of roots, leaving tubers in the ground from which new plants emerge quickly.