During the course of our study on the borderline of pharmaceuticals to non-pharmaceuticals, the morphological features and the internal transcribed spacer (ITS) sequences in the nuclear rDNA of Sida plants and the crude drugs/health foods so called Sida products were investigated. As the results, we revealed that 7 of 11 products tested contained Sida plants and 3 products among them included the other plant material(s) together with Sida. The ITS sequences of Sida plants observed in this study were classified into 6 genotypes. One of them is identical with that of Sida fallax whereas the others had no identical sequence on the international nucleotide sequence databases. On the other hand, other species including Urena, Malva and Triumfetta plants of the family, Malvaceae were detected from 7 products. In field survey on Oahu Island, the state of Hawaii, USA, Malvaceus plants possessing a Sida like flower were observed at the same place together with Sida plant. This growing environment in field is likely to be one of the reasons for the contamination in the products. Simultaneously, our field survey suggests that the appearances of the flowers were not critical points for the identification of Sida plants. Based on microscopic observations, we found that the stellate hair on leaves and the features of mericarps were suitable for the purpose. In conclusion, the exact identification of their botanical origin is important for regulation of Sida products on the borderline of pharmaceuticals to non-pharmaceuticals.
