Plant medicine is practiced widely across the world, however, there is concern that introduced plants could be replacing the use of native plants for medicine in various regions. It is critical to understand the potential influence of introduced plant use on native plant treatments. With hundreds of thousands of native plant treatments used by indigenous peoples worldwide that have yet to be fully examined, there is a likelihood that cures for many common maladies such as hair loss, arthritis, dementia and even cancers might already exist. This research provides valuable information for possible approaches to preserving that rich cultural knowledge.

To better understand why people select non-native plants for medicine, Georgia Hart, a PhD student in the Department of Botany at the University of Hawaiʻi at Mānoa, led a group of international ethnobotany researchers on a bioinformatics project focused on medicinal plant use in Ecuador.

The team studied the use of introduced, or non-native, plants for medicine in Ecuador, using a bioinformatics approach to generate new understanding in ethnobotany by synthesizing information from two large databases. The first database, The Catalogue of Vascular Plants of Ecuador, includes more than 17,000 plant species. The Catalogue of Useful Plants of Ecuador is a compilation of more than 40,000 recorded medicinal plants uses, accrued over centuries.

Ecuador is one of few megadiverse countries in the world. It is also highly culturally diverse with more than 17 ethnic groups and languages spoken. Use of plant medicine is common in Ecuador, including among the mestizo, or racially mixed, population. This context and these databases provided an ideal repository of information for the international team.

The strong correlation between medicinal use of plants and cultivation suggests home gardens and agroforests should be protected for the valuable human health resources they provide in Ecuador.

What the authors found was that introduced plants are selected much more often for medicine than would be predicted based on their abundance. Why was this the case? The availability of introduced plants was important in their selection, mostly as it relates to cultivation. Introduced plants also tended to treat illnesses that few native plants treat. Finally, introduced plants, on average, treated more conditions than native plants. It therefore appears that introduced plants are sometimes selected in ways that could supplant native plant use. The strong correlation between medicinal use of plants and cultivation suggests human-mediated environments such as home gardens and agroforests should be protected for the valuable human health resources they provide in Ecuador.

The team’s research, “Availability, diversification and versatility explain human selection of introduced plants in Ecuadorian traditional medicine,” was recently published in the journal PLOS ONE. The team included two UH Mānoa botany faculty, David Cameron Duffy and Orou G. Gaoue, as well as seven other faculty and researchers from the Pontificia Universidad Católica del Ecuador, Aarhus Universitet in Denmark, Universidad Autónoma de Madrid in Spain and the Missouri Botanical Garden.

—By Tony Hall