The genus Ambrosia is native to North America but a couple of the species are native in other places in the world and several species have become successful weeds worldwide (see below). The common name, Ragweed, is well known to those who suffer from allergies because the pollen from many of the species in this genus is the culprit for seasonal (mostly spring and early summer) allergies. Ironically, this plant appears to be, in the author’s experience, the most potent plant available for the effective amelioration of symptoms associated with hay fever including itching eyes and sinus [congestion], sneezing, scratchy throat, etc. Some Western herbalists swear by the prophylactic application of Ambrosia sp., providing a moderate dose (15-45 drops) of the tincture a couple of months prior to the patient’s allergy season.
The primary plant in the monograph, Ambrosia dumosa, is the species I have the most experience with and I consider it to be more potent than other species. Nevertheless, manyMany of my colleagues who have more experience with other species have suggested that they find those species to be more than adequate for the above use. One of these, A. artemesiifolia, is probably the most commonly used species, and I have also found it to be useful in the same way as the primary species is described above. However, my experience with A. artemesiifolia is far too limited to compare them in specific ways. This species (A. artemesiifolia) has the added of havingbenefit ofhaving a far greater range, including naturalization in China. While A. dumosa is only found in the southeastern portions of California, southern Nevada, most of western Arizona, and only the furthest southwestern portion of Utah, as well as northwestern Mexico, A. artemesiifolia is found throughout the United States and A. psilostachya can be found throughout much of North and Central America, part of South America, as well as Western Europe, Australia, and South Africa. The use of organoleptic observation will provide insights into the potency of the various species. From my observations, the more acrid and aromatic species tend to be more drying and fast acting, both in the treatment of phlegm and in coursing wind. I have found that most to least bitter and acrid specie are (in descending order, A. dumosa, A. psilostachya, and A. artemesiifolia.