Echinacea (also known as purple coneflower or snakeroot) is a perennial plant with a stout, hairy stem 2 to 3 feet in height. The leaves are thin, rough, and hairy, growing 3 to 8 inches long. Found throughout Midwestern North America from Texas to Saskatchewan, echinacea flowers from July to October, bearing a large, cone-shaped blossom which may range in color from whitish-pink to a pale purple. Of the nine species of echinacea that have been identified, three (angustifolia, purpurea, and pallida) are used for health purposes.
There are several compounds in echinacea that may be active in the body, including echinacoside, cichoric acid, polysaccharides, alkylamides, polyacetylenes, flavonoids, essential oils, resins, glycoproteins, sterols, and fatty acids. Levels of these compounds vary with growing conditions and between different species. Because compounds occur in varying concentrations in different parts of the plant, many herbalists recommend whole-herb extracts that use both the above-ground and underground portions.
The recommended dosage for echinacea varies with the quality and the portions of the plant used and with the extraction methods used in preparation. Most echinacea supplements have dosage recommendations printed on their labels. The herb has an excellent safety record, with no known side effects. Echinacea has no known toxicity, even at several times the normal therapeutic dose.