DNA Barcoding for the Identification of Phyllanthus Taxa Used Medicinally in Brazil.

Plants of the genus principally , and are used in Brazilian folk medicine to treat kidney stones as well as other ailments, where the latter two species are listed in the Brazilian Pharmacopeia as (). However, only has been shown to be effective in a clinical setting. Nuclear ribosomal internal transcribed spacer (ITS1 - 5.8S rRNA-ITS2), internal transcribed spacer 2, and chloroplasts L, K, A-H, L, and L-F were screened for their potential as DNA barcodes for the identification of 48 taxa in Brazilian medicinal plant germplasm banks and in "living pharmacies". The markers were also tested for their ability to validate four commercial herbal teas labelled as . Using the criterion of high clade posterior probability in Bayesian phylogenetic analysis, the internal transcribed spacer, internal transcribed spacer 2, and chloroplast K, A-H, L, and L-F markers all reliably differentiated the four species, with the internal transcribed spacer and K possessing the additional advantage that the genus is well represented for these markers in the Genbank database. However, in the case of L, posterior probability for some clades was low and while and formed monophyletic groups, and accessions could not be reliably distinguished with this marker. Packaged dried herb from three Brazilian commercial suppliers comprised , but one sample was also found to be mixed with alfalfa (). An herb marketed as from a fourth supplier was found to be composed of a mixture of and .