西方草藥－紫錐花（Echinacea）的栽培與利用

Echinacea species, a popular medicinal herb throughout the world, have been used by indigenous Americans for hundreds of years as an effective immunostimulant. The cultivated acreage in the United States, Canada and Europe is increasing because of the great demand for Echinacea products. Better cultural methods and standardization and quality control of the value-added products are needed to increase the confidence of growers, producers, and consumers in this promising medicinal herb. Echinacea can be propagated from seed, crown division, and root sections. Seed stratification for 4 to 6 weeks (1 to 4℃) before planting can improve germination. Echinacea thrives under cultivation in moderately rich and well-drained loam or sandy loam soil with regular irrigation and weed control. Roots are harvested in the fall after 3 to 4 years of cultivation in temperate region. The best stage to harvest flowers has yet to be determined. Leaves are a source of valuable active ingredients, but no information is available in the literature on leaf harvesting. Active ingredients in Echinacea include polysaccharides, flavonoids, caffeic acid derivatives, essential oils, polyacetylenes, and alkylamides. Some of the information in Taiwan (subtropical area) is also included.