Order
Compositae

Habitat
North American prairies, plains, and open woodlands.

Constituents
Glycosides, Echinocides, Polysaccharides, Alkylamides (mostly isobutylamides which cause the characteristic tingling in the mouth), Inulin, polyacetylenes. 
Essential oils: humulene, caryophyllene.
Miscellaneous: vanillin linolenic acid derivatives, a labdane derivative, alkanes and flavonoids and the alkaloids tussilagine and isotussilagine. Resins and Betain.

Part used
Root and rhizome.

Actions
Immunomodulator, anti-microbial, anti-viral, (antiviral and antibacterial activity is as an indirect result of immune enhancement), anti-inflammatory, vulnerary, lymphatic, anti-catarrhal, alterative.

Can be used for
Upper respiratory tract infections, surface immune tonic, boils, acne, abscesses, furunculosis, sore throat; mild septicemia, streptococcal and staphylococcal infections generally. Ulcers of tongue, mouth, gum, tonsils and can be used as a mouthwash for the treatment of pyorrhea and gingivitis.
Systemic candida, infections of the fallopian tubes. Ill effects of vaccinations.
A complex polysaccharide called echinacin B. is involved in regeneration of connective tissue destroyed during infection and in the elimination of pathogenic organisms creating the infection. States of weakened, suppressed or imbalanced immunity, including allergies an auto-immune disease. Topically can be used for the treatment of poor healing wounds, inflamed skin and bacterial infections.
May be used to increase phagocytosis, and as adjunct therapy during cancer treatment.

Preparations
Liquid extracts of fresh or dried root or rhizome, tablets capsules. Topically, creams, lotions, skin washes.

Dosage
Decoction: place 1 - 2 teaspoonfuls of the root in one cup of water and bringing slowly to a boil, let simmer for 10-15 minutes. Drink decoction three times a day.
Tincture: (1:3 or 1:4  @ 45% alcohol) take 1-4 ml three times a day. In acute conditions, these dosages may be increased in the short term
Duration of use: there is no evidence suggesting that long term usage will have an adverse effect on immune function.

Toxicology
Laboratory  tests and necropsy findings in rats administered with doses many times  the human therapeutic dose, for 4 weeks showed no evidence of toxic effects.
Side effects are generally not expected in oral or topical use. Contact dermatitis may occur but very rarely in susceptible patients.

Contraindications
Caution should be exercised in people allergic to Compositae plants.
The British Herbal Pharmacopoeia (1983), and the British Herbal Compendium have no contraindications for Echinacea. Dr. Weiss suggest that Echinacea can do no harm and has no side effects.
The German Commission E monograph states that in principle echinacea should not be used in progressive conditions such as: AIDS, HIV infection, tuberculosis, leukemia, MS, and other auto-immune conditions. The key words in these caution is in principle, as there is no one clinical study documenting an adverse effect as a result of using Echinacea in any of these conditions. 

Special warnings and precautions
Cautions should be taken with transplant patients taken immunosuppressive drugs, only short term therapy is suggested.
No evidence suggests that long term use is detrimental to immune function.

Interactions
None known.

Use in pregnancy and lactation
No data available. Although the commission E recommends limitations on Echinacea use, several authoritative sources do not support these restrictions.

Side effects
No side effects are generally expected for oral or topical usage, as indicated above, contact dermatitis may occur (rarely) in prone patients.

Overdose
Not known.

Bibliography

Bartram, T. 1995 Encyclopedia of Herbal Medicine First Edition Grace 
BHMA, 1983 British Herbal Pharmacopoeia, BHMA, Bournemouth.
Grieve, M. 1971 A Modern Herbal, vol. 1 Dover publications N.Y.
Hoffmann, D. 1990 The New Holistic Herbal, Second Edition, Element.
Mills, S. Bone K. 2000 Principles and Practice of Phytotherapy Churchil Livingstone
Weiss, R.F. 1991 Herbal Medicine, Beaconsfield Arcanum, Beaconsfield.

NOTE: I hope you will find the herbal  monographs informative and interesting,  but please remember that descriptions of herbs and usages are not meant to replace the diagnosis and treatment of a qualified practitioner.
I cannot accept responsibility for any adverse effects arising from self-medication. Do not self treat if you are pregnant or breast feeding, or if you are taking any medication. Any persistent condition should always be referred to a medical herbalist or doctor.