In this paper we use two disparate examples to highlight the relevance of historical methods in the context of ethnobotany and ethnopharmacy. The history of pharmacy - as it relates to phytotherapy and medicinal plants - has had a strong interest in what anthropologists would call ‘cultural practises'. The antiquity of medicinal plant uses in the Olmec region in Mexico was studied by comparing the pharmacopoeias of the linguistically related Lowland Mixe and Zoque-Popoluca. These cultures, separated for about 2000 years, have cognates for vernacular medicinal plant names in common. For fifteen species such cognate names were detected. Also, a statistically significant segment of the medicinal flora is used for similar purposes. Overall, 123 species are shared between the two groups and 62 of these have a similar usage. These findings make a transmission of such knowledge since the time of the Olmecs highly likely.
The Ch'orti' of Eastern Guatemala provide another interesting example of the relevance of historical data. Cultural anthropologist Charles Wisdom compiled an unpublished MS with many tentatively identified medicinal plant species used in the region in the 1930s - a rare chance for an ethnopharmacist.
Overall, these data indicate that we need to ascertain that such information is publicly available in order to safeguard the original keepers of knowledge and their rights.