Echinacea Extract: The Plains Indians of North America, used the plant for snakebite, anthrax and for their relief of pain. In the late 1930s, it became a common medicine for the common cold and it's related symptoms. 

All the tribes of that era used it for analgesics (pain).  The tribes claim that they watched the animals seek out this plant when they were sick or wounded. At that time it was called Elk Root.

All the following "cone flowers" are considered Echinacea Plants;
Topeka Purple Coneflower
Smooth Coneflower, Smooth Purple Coneflower
Pale Purple Coneflower
Yellow Coneflower, Bush's Purple Coneflower
Purple Coneflower, Eastern Purple Coneflower
Sanguine purple Coneflower
Wavyleaf Purple Coneflower
Tennessee Coneflower

All these varied species are beneficial to different parts of the body and it's function.

They all have some immunity benefits and when taken at the first signs (symptoms) of a cold or flu, can actually lessen the effects and shorten the time spent ill.

For children between the ages of 1-12 years of age, it is not recommended for use, as the immune systems of the very young is still developing.
 
Adverse Side Effects:  Not recommended for nurshing mothers or pregnant women.  It is advisable to not take Echinacea for a long period of time.  Ususall longer than 10 days.