Cyperus rotundus: Nut grass

Family: Cyperaceae
Common name: Nut grass, Coco grass, Java grass, Purple nutsedge, Red nutsedge, Purple nut sedge

Nut grass or Coco grass is a colony-forming perennial plant, a widely distributed weed that can be found in various continents like Asia, Africa, Europe, and Australia. The plant has a small, brown, rounded tubers that looks like a nut, giving the plant its name nut grass.

Their roots are an elaborate network of bulbs, tubers, fibrous roots, and thin long rhizomes. The stem is slender, erect, growing to a height of 40-60 cm. It divides into small branches at the tip, each branch holding up the flowers.

The leaves are long and narrow, about 20-35 cm long and tapered at the ends, with a prominent, sunken midrib. Nut grass plants produce small, purple-brown flowers that grow in clusters at the end of the stem. Pollination is mainly by wind, and after pollination, the flowers produce tiny, brown, triangular seeds.

Nutgrass plants can sprout, flower, and fruit with 6-8 weeks making them extremely hard to hand-pluck and remove completely. They have a strong and pungent aroma, which comes from their essential oil content which contains several bioactive compounds.
These compounds possess antioxidant, anti-inflammatory, antimicrobial, and antitumor activities making the plant very useful in traditional herbal medicine.

Nut grass plants are used to treat ailments like fever, diarrhoea, inflammation, malaria, stomach ailments, dysentery, and respiratory infections. They possess diuretic and anti-diabetic properties and has been used to treat urinary tract infections, diabetes, and high blood pressure. The essential oil of Nut grass plants are used to relieve pain, reduce inflammation, and promote wound healing.

Despite its medicinal properties, Nut grass plants are considered a noxious weed in many parts of the world. It can be difficult to control, as they reproduce rapidly through its tubers, which can regrow even after they are removed from the soil. Nut grass plants usually die in winter, getting resurrected from dormant tubers when favourable conditions arise.

They prefer warm, tropical conditions though they can tolerate a wide range of temperatures and soil types. This plant can invade crops and reduce crop yield, and it can also compete with native plant species for resources.

The underground tubers absorb all the nutrients in the soil thus robbing surrounding plants and destroying them. Nut grass plants are one of world’s worst weeds affecting crops in over 90 countries worldwide.

Propagation is through tubers and seeds.