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Herb Gallery

Bai Mao Gen (Imperata cylindrica)

  • Botanical name: Imperata cylindrica
  • Common name: Imperata rhizome, Woolley grass
  • Family: Gramineae, grass family
  • Part used in Chinese medicine: rhizome
  • Major Chinese medicine actions:
  • Cools blood, stops bleeding, clears heat, promotes urination,
    clears heat in Lungs and Stomach
Imperata cylylindrica

Photo Credits:
Photo 1: Imperata cylylindrica; 09/2008; author C. Micleu; permission Jade Institute

Growing and Propagation

The plant is best grown in moist, humus-rich, well-drained soil, in full sun or light shade. Growing slowly, it spreads by forming loose grassy clumps up to 16 inches high and 12 inches wide. Imperata requires long hot summer sun in order to flower with its characteristic long, fluffy, white spikes. In cooler regions the plant will often grow well but not flower.

Propagation is best done by division in spring or early summer. The plant is hardy in USDA zones 3 to 9 and in cold climates it requires mulch, especially for young plants. Care should be taken in hot climates where the plant grows especially vigorously as it can become invasive.

Harvesting and Preparation

For medicinal use, good quality Bai Mao Gen has thick white rhizomes that are sweet in taste.


The genus Imperata consists of six species of slender stemmed perennial grasses that originate in tropical and warm temperature regions. Imperata cylylindrica “Rubra” (photo above) is known by its common name Japanese Blood Grass, and is widely grown as a garden perennial for its striking foliage.