Herbal products, such as dietary supplements, have become a subject of increasing global importance for their health benefits and economic considerations. However, they have also been targets of adulteration practices, being the accurate identification of botanicals in herbal products of utmost importance to protect the health and expectations of consumers. Particularly, in the case of dietary supplements, which can have different types of formulations, the identification of plant material used in their production is often a research challenge. DNA‐based techniques have played a crucial role on the development of a wide range of tools for the authentication of herbal products. Therefore, this review intends to describe their main progresses, critically discussing their advantages and drawbacks when applied to authenticate herbal products, focusing on dietary supplements. DNA barcoding is particularly emphasized because it has provided the highest number of applications, followed by the advances on high‐resolution melting analysis combined with DNA barcodes. A special emphasis is also given to the promising approaches relying on DNA metabarcoding and isothermal amplification.

An ethnobotanical survey of medicinal plants used by the Sobradinho community, Luís Correia, Piauí, Brazil was undertaken to recover and document traditional knowledge with the aim of supporting chemical, biological, agronomic, pharmaceutical and socio-economic studies related to the region's biodiversity. Fifteen research visits to the community were made between March 2013 to January 2014 involving 31 respondents from the community, the majority (74.4%) being women aged between 27 and 84 years. The methodology used was interview by the snowball method using questionnaires. Analysis of the data gathered was based on use value and the Shannon-Wiener diversity index. Botanical voucher specimens were made of the species cited by informants and deposited at the HDELTA herbarium. 57 species belonging to 33 families were identified, of which 56% were native and 44% exotic. The best represented families were Fabaceae (14%), Lamiaceae and Myrtaceae (9% each). The leaves were the most frequently used plant parts (69%), followed by the stem (22%), fruit (4%), flower (2%), root and seed (1%). The species that showed the highest use value (VU) were Cymbopogon citratus (DC.) Stapf (capim-santo) and Morinda citrifolia L. (noni) with VU = 0.26. The Shannon-Wiener index value was highest for the elderly group (n=15, 48% of total respondents), but young people were not represented among the informants. A total of 67 different medicinal indications were recorded, the highest number of species being used to treat medical conditions associated with inflammation, pain and fever. Informants claimed to have learned the use of medicinal plants from older members of the community and there was little interest evident among young people in acquiring this knowledge. Community informants are the holders of medicinal plant knowledge of the local flora and its practical application. Key words: Biological diversity, ethnobotany, floristics, medicinal plants, Piauí.