Botanical name: Cyperus rotundus
Common name: Cyperus, Nut-grass, Purple nutsedge
Literal name translation: aromatic appendage
Family: Cyperaceae, sedge family
Part used in Chinese medicine: rhizome
Major Chinese medicine actions:
Moves and regulates Liver qi, regulates menstruation
and alleviates pain
Photo Credits: (top to bottom)Photo 1: Cyperus rotundus; 12/2006; author Rickjpelleg; permission under GFDLPhoto 2: Cyperus rotundus; 06/2007; author Hamasuge; permission under GFDLPhoto 3: Cyperus rotundus; 12/2006; author Rickjpelleg; permission under GFDL
Cyperus is a perennial grass-like herb indigenous to Africa, southern and central Europe and southern Asia, but is now found around the world in temperate climates. It grows to 30 inches tall, has purple-brown flowers and tuberous roots or rhizomes that are quite fragrant.
The plant is one of the most invasive weeds known and has infested over 90 countries worldwide. It aggressively competes with other nearby plants for ground nutrients, and its roots release substances harmful to other plants. It is difficult to control because of its very extensive system of underground tubers, and because of its resistance to most herbicides. Pulling up the plant usually results in breaking the roots, leaving the tubers in the ground to grow new plants.
Growing and Propagation
Cyperus grows best in full sun, and will thrive well in any soil type. It is frost sensitive and hardy in zones 9 to 11. Propagation is by seed and rhizome.
Harvesting and Preparation
For medicinal use, the rhizomes are harvested and cleaned. Large, hard rhizomes with intense fragrance are considered the best quality. Small, lightweight, wrinkled rhizomes are poor quality.