Echinacea Echinacea spp. Prairies, plains, and open woodlands. Purple Coneflower microbial infections; colds; flu root Decoction: one to two tsp of the root to one cup of water, boiled and simmered for 10-15 minutes. glycosides anti-microbial; immunomodulator; anti-catarrhal; alterative Excellent for helping to prevent illness. Good for upper respiratory tract infections such as laryngitis, tonsillitis, runny nose and sinuses. Seems to act directly against foreign microbes, giving the immune system time to kick in. Also seems to stimulate the immune system itself. Should not be taken habitually, as if an immune booster. Works best when used seldom, and only at the onset or early initial stages of contracting an illness. If used carefully in this way, the herb can help prevent a cold completely. If used too routinely, however, it loses its effect.