T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Cyperus rotundus (Purple nutsedge)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Cyperaceae
Genus: Cyperus
Species: C. rotundus
Binomial name: Cyperus rotundus
Common names: Purple nutsedge, Nut grass, Coco-grass, Java grass, Purple nut sedge, Red nut sedge.

Cyperus rotundus is one of the world’s worst weeds of cropping land. It originates from Africa, southern and central Europe and southern Asia. It forms very dense colonies that smothers other plants, removes nutrients and moisture from soil. Rhizomes penetrate through asphalt paths and plastic sheeting and through vegetables such as potatoes and carrots which makes their harvesting difficult. Its dispersal is mainly by cultivation equipment. Locally it is spread by rhizome & tuber growth.

Cyperus rotundus is an erect perennial rush with distinctive smooth, dark green leaves with a prominent vein on underside are up to 20 cm long. It grows to about 50 cm tall and it has extensive root system of rhizomes and tubers. The plants three sided, flower stalks grow up to 60 cm tall. The red to purple flowers are bisexual. The flower head having 3–8 unequal rays and they develop January and March. The fruit is a three-angled achene.

A Cyperus rotundus tuber, approximately 20 mm long.

The three sided, flower stalk.

Thanks to Wikipedia for text and information     https://creativecommons.org/licenses/by-sa/3.0/