Astragalus is an herb native to China. It has been used by traditional Chinese medicine for many centuries. In the past thirty years, astragalus has been becoming more familiar in the U.S.
Out of the 2,00 or more species of astragalus, there are two in particular that are used to augment health. These are known by the Latin names Astragalus membranaceus and Astragalus mogholicus.
In China, astragalus is often used for colds and infections of the upper respiratory system. Along with these milder conditions astragalus is also used against some of the bigger guns like chronic hepatitis, heart disease and cancer.
Astragalus is usually used along with other herbs for enhancement of the immune system. "There is some preliminary evidence to suggest that astragalus, either alone or in combination with other herbs, may have potential benefits for the immune system, heart, and liver, and as an adjunctive therapy for cancer."
Astragalus is also known as bei qi, huang qi, ogi, hwanggi, and milk vetch.
http://nccam.nih.gov/health/astragalus/?nav