Here’s a little on Goldenrod (Solidago sp.) from the commentary in Thomas’s up-coming book.
Solidago is a genus of about 120 species with a center of biological diversity in North America. There are a handful of species in Mexico and South America and Europe, but only three species native to China. All three species are, or have been used in medicine with, not surprisingly, similar indications (see below for translations).
Although the center of biological diversity may be in North America, review of the literature clearly shows that across the globe, where there is a species of Solidago, there is some record of medicinal use. And, once more, the continuum of usage across the genus is striking. There are no less than 10 species used in medicine (probably a lot more) from 4 continents and the overwhelming majority of the usages for these species are the same or similar. One study published in 1985 (Flavonoids of Solidago canadensis and S. virgaurea V. S. Batyuk and S. N. Kovaleva) states, “Thus, free flavonols and their biosides have been detected in S. canadensis and S.virgaurea. The flavonoid compositions of the species of goldenrod studies are similar to one another; differing only by the ratios of the individual components.” The importance of this statement is not so much in the recognition that these two plants have similar (often the same) chemical components, but also that these species are native to North America and Europe respectively and the geographical disparity of their locale and similarity of both their usage and chemistry might suggest that other plants within the genus, also having similar documented usage, might also have similar chemistry. There is a lot that we do not know about this genus, but what we do know, clearly shows that the species within this genus are both useful and safe. It is noteworthy that the major species mentioned in Chinese medicine (S. decurrens) is also native to a number of other surrounding countries, including Russia where there appears to be a significant amount of research available. Unfortunately at this time I am unable to access this information due to the language barrier.