The authentic sources of RA and RAS. (a) A. membranaceus and (b) A. membranaceus var. mongholicus are the sources for RA. (c) H polybotrys is a common substitute for RA. (d) A. sinensis is the source for RAS. (e) A. acutiloba and (f) A. gigas are also sold as raw materials for RAS in the markets.