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12(1): Medicinal and poisonous plants 1

Cyperus L.

Sp. pl. 1: 44 (1753); Gen. pl. ed. 5: 26 (1754).

CYPERACEAE

x = 8, 9; Cyperus brevifolius: n = 9, 2n = 32, 120, Cyperus iria: n = 36, 56, 64, 2n = 18, Cyperus kyllingia: n = 43, 62, Cyperus rotundus: n = 40, 42, 48, 50, 54, 56, 64, 69, 76, 2n = 16, 26, 96, 108, 152

Major species Cyperus kyllingia Endl., Cyperus rotundus L.

Nut sedge, nut grass, cyperus (En). Indonesia: teki. Malaysia: teki. Thailand: ya kok, ya haeo. Vietnam: c[os]i, l[as]c.

Cyperus comprises about 600 species distributed worldwide, with the vast majority occurring in the tropics and subtropics. In Malesia 76 species occur, but most of them have a pantropical or paleotropical distribution.

In general, Cyperus is economically unimportant and better known for its weeds than its useful plants; several species are pernicious weeds in agriculture.
Several of the weedy species, particularly Cyperus rotundus, are used in local medicine. In South-East Asia, the most widespread medicinal applications of the tubers are against hepatic disorders, as an emmenagogue and for post-partum treatment, as a stomachic, as a febrifuge, against renal and urologic disorders, and to treat ulcers. It is interesting that Cyperus species are used in similar ways in other parts of the world, e.g. in South America. Other medicinal uses in South-East Asia are as a stimulant, diuretic, anthelmintic (in large doses), galactagogue, sudorific, as a mouthwash against diseases in the mouth and toothache, and as an astringent against diarrhoea and dysentery.
Usually the powdered tubers (often in decoctions) are used internally, but for ulcers, scorpion stings and snake bites a poultice is applied externally. Cyperus species are also well known in Chinese and Japanese traditional medicine and are reported to be used in India as stimulants, diuretics, anthelmintics and stomachics for example. In the Ayurvedic system of medicine the tubers are believed to be tonic, and to act as a nourisher and rejuvenator; they are part of several complex preparations.
Because of their aroma, the tubers are used to perfume clothing and to repel insects. The roasted tubers have also been used as a substitute for coffee and as an adulterant for cocoa.
The fatty oil extracted from the tubers was formerly used to make soap. The dried stems are used to make mats, ropes, baskets and other wickerwork. Tubers and aboveground parts can also serve as a forage. Some species are used for their edible tubers (especially in times of food scarcity), for their edible stems (as vegetable or as forage), and some are used as garden ornamentals.

All Cyperus species are considered as weeds that are difficult to eradicate. Cyperus rotundus is considered to be one of the world's most pernicious weeds. The sole medicinal use of the tubers of this species is in local medicine.

The underground parts of several weedy species contain essential oils, about 0.5-1% in the case of the fresh tubers of Cyperus rotundus, mainly consisting of terpenoids or sesquiterpenoids (e.g. cyperone, cyperol, cyperolone, cyperene, copadiene, epoxy-guiaene, rotundone, rotundol, patchoulenone (= cyperotundon), kobusone, sugeonolacetate, sugetriol, oxido-eudesmenol, mustakone and 'BETA'-selinene).
When Tanzanian medicinal plants were screened, Cyperus rotundus showed activity in a test for in vitro antimalarial activity. Further phytochemical investigations revealed the presence of several active compounds: 'ALFA'-cyperone, an auto-oxidation product of 'BETA'-selinene, patchoulenone, caryophyllene epoxide, 4,7-dimethyl-1-tetralone (all sesquiterpenes) and 10,12-peroxycalamenene (a sesquiterpene endoperoxide). There is evidence that the peroxide moiety of the latter molecule is important in the activity against malarial parasites, as are artemisinin (from Artemisia annua L.) and ascaridole (from Chenopodium oil).
The essential oils furthermore have nematicidal and insecticidal activity (e.g. against bugs, beetles and caterpillars), and the insect- repellent activity is comparable to that of citronella oil. The aggressive spread as a weed may also be partly attributed to the sesquiterpenes present in the oil, which inhibit the growth of seedlings of agricultural crops.
Several investigations have focused on the anti-inflammatory and/or anti-pyretic effects of Cyperus rotundus. Preliminary observations were made on the ethanolic extracts of the roots. The mechanism of activity was subsequently found to be inhibition of prostaglandin synthesis. In addition to the effects mentioned, some antihistaminic, smooth muscle relaxant, anti-emetic, antihepatotoxic and antifungal activities were observed. A carrageen-induced oedema test in rat revealed that the triterpenoid in the light petroleum ether extract of the root is the main active compound with in vivo anti-inflammatory activity.
Small amounts of saponins have been reported from Cyperus rotundus, and the main substance of the lipid fraction in tubers of Cyperus iria has been shown to be hentriacontanol. In Malaysia, a compound isolated from a steam distillate of the whole plants of Cyperus iria appeared to be identical to juvenile hormone produced by insects. Nymphs of the acridid Melanoplus sanguinipes feeding on Cyperus iria showed pronounced morphogenetic effects when they moulted to adults, so the compound can be considered as the plant's defence mechanism against insects. The water extract of rhizomes exhibits bradycardia and cardia depressant, coronary vasodilator, hypotensive and diuretic activities. Clinical trials with root extracts in 64 obese patients found hypotensive activity in those patients with hypertension, but no effect in normal patients.

The following species combine several of the major applications of Cyperus: Artemisia spp. (e.g. emmenagogue, stomachic, febrifuge, diuretic and ulcers), Desmodium spp. (e.g. hepatic disorders, stomachic, febrifuge, diuretic and ulcers), Hibiscus spp. (e.g. emmenagogue, stomachic, febrifuge, diuretic and ulcers), Elephantopus scaber L. (e.g. emmenagogue, febrifuge, diuretic and ulcers), Heliotropium indicum L. (e.g. emmenagogue, stomachic, diuretic and ulcers), Leonurus spp. (e.g. emmenagogue and for post-partum treatment, febrifuge and diuretic) and Tinospora spp. (e.g. hepatic disorders, stomachic, febrifuge and ulcers). However, the active compounds are in general quite distinct and the similar medicinal use is not a result of chemical conformity. Chemically related substances are found in some grass genera such as Cymbopogon; their essential oils have very similar sesquiterpenes and some similar applications.

Perennial or annual herbs, tufted or with creeping rhizome or stolons, sometimes with tubers at intervals; stem usually erect, triangular in cross-section, solid, usually leafy only at the base. Leaves tristichous, narrowly linear, grass-like, the lower ones often scale-like. Inflorescence terminal, simple to decompound, umbel-like or capitate; rays subtended by a leaf-like bract forming an involucre; spikelets subcompressed, quadrangular to subterete, 1-many-flowered; glumes distichous, usually 2 basal ones empty. Flowers bisexual, the uppermost of the spikelet often male or sterile; stamens 1-3; style continuous with the ovary, with 2-3 stigmas. Fruit a sessile or short-stalked nut, trigonous or lenticular.

Most Cyperus rotundus plants originate from a tuber; seed production is possible but unimportant. The sprouting tuber produces a rhizome which terminates as a green aerial shoot. While emerging from the soil a swelling (usually called a 'basal bulb') appears on the rhizome, often near the surface, but up to a depth of 20 cm. Roots form on the basal bulb and rhizomes grow out from it horizontally for a distance of 1-30 cm before the tip turns up to produce a new aerial shoot with another basal bulb, or, alternatively, to form a subterranean tuber from which another rhizome appears at the apical end, thus forming chains of tubers. The basal bulb and aerial shoot population may increase fivefold in the first 4 weeks after a tuber has been planted. It is believed that there are no buds at the nodes of the rhizomes and that no new plants can grow from rhizome fragments. Rhizomes and tubers are white and fleshy when young and some become firmly packed with starch. On aging they darken, harden, and most of the tissue outside the endodermis of the rhizomes sloughs off to leave a wiry structure resistant to desiccation and decay. Most tubers are found in the top 15 cm of the soil, and when planted at 90 cm depth are unable to grow to the surface. In cropped areas the starch reserves are greatest in tubers that are below the disturbed layer; in uncropped land they are greatest in tubers near the soil surface.
Short photoperiods stimulate flowering; the period from emergence to flowering varies between 3-8 weeks. Short photoperiods might also stimulate tuber formation and it is believed that tubers do not form until flowering begins. Flowers are cross-pollinated, mostly by wind. Although many seeds are formed, they are rarely viable: seed germination averages 1-5%.
Cyperus iria spreads by seed that may germinate immediately as soon as it falls on the ground. Germination percentage is about 40% but is much lower if the soil is under water.

Cyperus is classified in the subfamily Cyperoideae and the tribe Cypereae. It seems to be most closely related to Bulbostylis and Fimbristylis. Cyperus is subdivided into 3 subgenera and numerous sections. Subgenus Cyperus includes most species in the Malesian Archipelago (about 60) and is characterized by a trigonous or, when lenticular, dorsoventrally compressed nut, and often 3 stigmas. Subgenus Pycreus includes 9 species in Malesia and has a laterally compressed nut, persistent rachilla and 2 stigmas. Subgenus Kyllinga, which has often been treated as a separate genus, includes 7 species in Malesia (e.g. Cyperus brevifolius and Cyperus kyllingia) and is characterized by its laterally compressed nut, disarticulating rachilla and 2 stigmas.

Most Cyperus species are hygrophilous and grow in moist or wet localities at low and medium altitudes, only a few occurring above 2000 m altitude in the tropics. Several species occur commonly in grasslands, on roadsides, river banks and waste places. Some species are noxious weeds in cropped land, and other species are colonizers of muddy and sandy flats near river mouths and along the coast. Cyperus rotundus is found in fields, on roadsides, in neglected areas, at the edges of woods, along irrigation canals and streams, all over the world up to about 50° latitude in both hemispheres, beyond which low temperatures limit its further expansion. It grows readily at any elevation, humidity, in almost any soil type, soil moisture and pH, and can survive very high temperatures. Only low temperatures, shade, and very saline soils can limit its growth, and the tubers can remain dormant for a long time to carry the plant through the most extreme conditions of heat, drought, flooding or lack of aeration.

All Cyperus species can be propagated by seed, and tuber-forming species can be easily propagated by tubers.

Some Cyperus species, especially Cyperus rotundus are serious weeds of rice, sugar cane, maize and vegetables in South-East Asia. Digging up all rhizome parts and/or the planting of crops that produce continuous shade for several years can eradicate them. Biological control methods have not yet been successful.

Cyperus rotundus has been reported as a host plant for Rhizoctonia disease and for root-knot nematodes (Meloidogyne spp.).

Cyperus rotundus may produce up to 40 t subterranean plant material per ha per year.

The tubers of Cyperus rotundus are briefly scorched by fire to get rid of the fine roots. They are then washed and dried in the sun or by hot air.

No germplasm collections and breeding programmes of Cyperus are known to exist.

It is expected that in South-East Asia Cyperus will primarily remain a weed problem for which effective herbicides and biological control methods still have to be found. It is not recommended to plant weedy species for medicinal purposes. Comparatively little research has been done on the chemistry and pharmacology. More research seems worthwhile on those Cyperus species used for similar medicinal purposes in many areas of the world.

Bulman, J.C., 1989. Cyperus rotundus L. In: Westphal, E. & Jansen, P.C.M. (Editors): Plant Resources of South-East Asia. A selection. Pudoc, Wageningen, the Netherlands. pp. 108-109.
de Padua, L.S. & Pancho, J.V., 1983. Handbook on Philippine medicinal plants. Vol. 4. Technical Bulletin vol. VI No 1. Documentation and Information Section, Office of the Director of Research, University of the Philippines, Los Baños, the Philippines. p. 29.
Holm, L.G., Plucknett, D.L., Pancho, J.V. & Herberger, J.P., 1977. The world's worst weeds, distribution and biology. East-West Center, University Press of Hawaii, United States. pp. 8-24, 240-243.
Kern, J.H., 1974. Cyperaceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Series 1, Vol. 7(3). Noordhoff International Publishing, Leyden, the Netherlands. pp. 592-661.
Mercado, B.L., 1979. A monograph on Cyperus rotundus L. Biotrop Bulletin No 15. Biotrop, SEAMEO Regional Center for Tropical Biology, Bogor, Indonesia. 63 pp.
Nguyen Van Duong, 1993. Medicinal plants of Vietnam, Cambodia and Laos. Mekong Printing, Santa Ana, California, United States. pp. 155-156.
Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha Publishing Co., Quezon City, the Philippines. pp. 112-115.
Shanmugasundaram, E.R.B., Akbar, G.K.M. & Shanmugasundaram, K.R., 1991. Brahmighritham, an Ayurvedic herbal formula for the control of epilepsy. Journal of Ethnopharmacology 33(3): 269-276.
Toong, Y.C., Schooley, D.A. & Baker, F.C., 1988. Isolation of insect juvenile hormone III from a plant. Nature, United Kingdom 333(6169): 170-171.
Vedavathy, S. & Rao, K.N., 1991. Antipyretic activity of six indigenous medicinal plants of Tirumala Hills, Andhra Pradesh, India. Journal of Ethnopharmacology 33(1-2): 193-196.

Nguyen Khac Khoi

Cyperus brevifolius
Cyperus cyperoides
Cyperus diffusus
Cyperus halpan
Cyperus iria
Cyperus kyllingia
Cyperus malaccensis
Cyperus rotundus
Cyperus stoloniferus

Nguyen Khac Khoi, 1999. Cyperus L.. In: de Padua, L.S., Bunyapraphatsara, N. and Lemmens, R.H.M.J. (Editors): Plant Resources of South-East Asia No 12(1): Medicinal and poisonous plants 1. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea

The following species in this genus are important in this commodity group and are treated separatedly in this database:
Cyperus brevifolius
Cyperus cyperoides
Cyperus diffusus
Cyperus halpan
Cyperus iria
Cyperus kyllingia
Cyperus malaccensis
Cyperus rotundus
Cyperus stoloniferus