Some common weeds of Manipur and their economic importance

Priyanka Irungbam, L Nabachandra Singh, Akoijam Ranjita, Konjengbam Sarda, Y Sanatombi and Y Bebila
Ageratum conyzoides
Family: Asteraceae
Common name: Goat Weed
Local name: Khongjai napi
Description
It is native to tropical America, especially Brazil, and is considered an invasive weed in many other regions. It is a herb 0.5–1 m high, with ovate leaves 2–6 cm long, and white to mauve coloured flowers. It is commonly found in the valley areas of Manipur and abandoned Jhum land.
Economic importance
The leaves and inflorescences are used in the preparation of a local shampoo called “Chenghi’’ for hair wash by Manipuri women, leaving the hair soft, fragrant and dandruff-free. It is also used as an insecticide and nematicide. Tannin extracts of goat weed showed insecticidal activity against flour beetles. The juice of the plant is used to treat cuts, wounds and bruises. The plant is used to treat constipation, infective hepatitis, eczema, epilepsy, fresh wounds, dizziness, diarrhoea, dysentery, sore eyes, fever, headaches, intestinal worms, filariasis, vomiting and nausea. The plant contains between 0.7-2.0% essential oil, plus alkaloids and saponins. The essential oil contained in the plant has antibiotic properties.
2. Alternanthera philoxeroides
Family: Amaranthaceae
Common name: Alligator Weed
Local name: Kabo napi/Phakchet
Description
It is a perennial herb, 50-120 cm long, with stem base like creeper, roots borne at joints, upper part erect and hollow with branches. It grows in ditches, ponds or on waste lands.
Economic importance
Shoot extract is given in dysentery. It is also consumed as a vegetable and used as poultry feed. Pharmacological works on the plant have showed that the extract of the leaves and stems have hypoglycemic, anti-microbial, anti-inflammatory and anti-arthritic effects.
3. Amaranthus viridis
Family: Amaranthaceae
Common name: Green amaranth
Local name: Chengkruk
Description
It is an annual herb with an upright light green stem that grows to about 60–80 cm in height. Numerous branches emerge from the base, and the leaves are ovate. The plant has terminal panicles with few branches and small green flowers.
Economic importance
It is eaten traditionally as a vegetable in Manipur. The plant is emollient and a vermifuge. A decoction of the entire plant is used to stop dysentery and inflammation, and also to purify the blood. The root juice is used to treat inflammation during urination. It is also taken to treat constipation. The pounded root is used against dysentery. The leaves are used in poultices (fresh or as dried powder) to treat inflammations, boils, abscesses, gonorrhoea, orchitis and haemorrhoids. The leaf sap is used as an eye wash to treat eye infections.
4. Bidens pilosa
Family: Asteraceae
Common name: Beggar Tick/Spanish needle
Local name: Hameng sam pakpi
Description
It is a tall branched weed with thin yellow flowers that develop into a cluster of barbed seeds. The seeds are like short and stiff hair. They get stuck in feathers, fur, socks, etc.
Economic importance
The plant is used to cure leprosy and various skin diseases. Seeds are anthelmintic, diuretic and used in kidney problems. Leaf juice is used for eye and ear troubles. Infusion of roots is given in colic. The plant extracts can be used for wound healing and treatment of breast cancer, and also has other properties like antibacterial, anti-inflammatory and anti-allergic and anti-malarial activity.
5. Centella asiatica
Family: Umbelliferae/Apiaceae
Common name: Indian pennywort
Local name: Peruk
Description
The stems are slender and creeping stolons, green to reddish-green in color, connect plants to each other. The leaves are borne on pericladial petioles of around 2 cm (0.79 in). The rootstock consists of rhizomes growing vertically down. The flowers are white or pinkish to red in color and born in small rounded bunches (umbels) near the surface of the soil.
Economic importance
It is consumed as a vegetable in Manipur. Juice of fresh plant with honey is given to cure stomach ulcers and urinary troubles. The plant is diuretic and tonic. Boiled extract of the plant is useful to treat digestive complaints and dysentery. Powdered leaves are used against skin diseases.
6. Cynodon dactylon
Family: Gramineae
Common name: Dhub grass, Bermuda grass
Local name: Tingthou
Description
It is a variable perennial, creeping by means of stolons and rhizomes. The blades are a grey-green color and short, usually 2–15 cm long with rough edges. The stems are slightly flattened, often tinged purple in colour. The seed heads are produced in a cluster of two to six spikes together at the top of the stem, each spike 2–5 cm long. It has a deep root system. It reproduces through seeds, runners, and rhizomes.
Economic importance
It destroys foulness of breath and is useful in leucoderma, bronchitis, piles, asthma, tumors and enlargement of the spleen. According to Unani system of medicine, Cynodon plant has a bitter and sharp hot taste, good odor, and works as a laxative, brain and heart tonic, aphrodisiac, alexipharmic, emetic, emmenagogue, expectorant, carminative and is useful against grippe in children and pain, inflammation and toothache. Extracted juice of the grass is applied to fresh cuts or injuries to stop bleeding. Women suffering from excessive uterian bleeding are given about 50 cc fresh juice  of the plant, along with sugar, once daily for three days as a remedy. Rhizome is used in genitor-urinary troubles.
7. Cyperus rotundus
Family: Cyperaceae
Common name: Motha, Purple nut sedge
Local name: Shembang kouthum
Description
It is a perennial plant that may reach a height of up to 140 cm. As in other Cyperaceae, the leaves sprout in ranks of three from the base of the plant, around 5–20 cm long. The flower stems have a triangular cross-section. The flower is bisexual and has 3 stamina and a three stigma carpel, with the flower head having 3–8 unequal rays. The fruit is a three-angled achene. The root system of a young plant initially forms white and fleshy rhizomes, up to 25 mm in dimension, in chains. It prefers dry conditions, but will tolerate moist soils, and often grows in wastelands and crop fields.
Economic importance
Tubers are diuretic, emmenagogue, antihelmintic, astringent and stimulant. It is useful in disorders of stomach and irritation of bowels. Plant decoction is useful in cardiovascular diseases and urinary troubles. Despite the bitter taste of the tubers, they are edible and have nutritional value. It is a staple carbohydrate in tropical regions for recent hunter-gatherers, and is a famine food in some agrarian cultures. Anti-microbial, anti-malarial, anti-oxidant and anti-diabetic compounds have been isolated and identified from C. rotundus.
8. Eclipta alba
Family: Asteraceae
Common name: Bhangra/Bhingraj, False daisy
Local name: Uchisumban
Description
It is a creeping herb about 3 m in height. It is annual, erect and branched herb often rooting at nodes. It has white coloured flowers with long stalk placed on short, flat and rounded stem. Leaves are opposite, sessile and lance shaped. Well-developed roots of this plant are cylindrical and greyish in colour. Floral heads are white in colour, solitary, winged narrowly and about 6-8mm in diameter.
(To be contd)