Morphological Assessment of the Identity of Selected Unprocessed Botanicals in Commerce

Abstract

Adulteration of botanical products has a few typical forms, including the accidental or deliberate substitution of one plant species for another. At the stage when unprocessed plant parts are purchased, this is the primary form of adulteration to the extent that such occurs. Whole botanicals are usually purchased on the wholesale market by intermediary processors, though current GMP testing requirements might make direct purchase of such botanicals economically advisable for some supplement manufacturers; there is also a retail market for unprocessed herbs, which are purchased by herbalists and private consumers. To explore the prevalence of adulteration of unprocessed bulk herbs, ten botanicals were chosen for study based on their unambiguous identifiability and, for most, literature reports of confirmed or possible adulterants. Eleven geographically diverse U.S.-based retail herb vendors were selected, and samples of the selected botanicals available in unprocessed form from each vendor were purchased and evaluated. For most species, including those with known potentially toxic or allergenic adulterants (star anise, skullcap, chamomile), no adulteration was observed. Most purchased samples of arnica and linden, and one sample of juniper, were wholly misidentified; for linden and juniper, the substitution was of unofficial species of the same genera. Because our selection of species was intentionally biased to increase the likelihood of detecting adulteration, we have no basis for estimating the overall rate of adulteration of unprocessed botanicals. However, adulteration is clearly a taxon-specific problem: most species are consistently correctly identified, but a few are frequently confused.