You may have heard of echinacea if you frequent the vitamin&herb aisle in pharmacies and health food stores. While some Native American tribes used echinacea to treat cold symptoms, research has been inconclusive. Part of the reason why research is so challenging with this plant is that there are so many species, and the chemicals in the plant vary wildly from plant to plant. Like many other herbs, you can take it in many forms, and for different amounts of time. It does, however, make a lovely addition to the garden, for purely aesthetic reasons.