The Accuracy of Plant Identification in a Longitudinal Ethno Botanical Project in Coastal Ecuador

Abstract

Background: Preserving traditional environmental knowledge about herbal medicine in the face of rapid environmental, economic and cultural change depends in part on the identification of traditionally used medicinal plants to their Latin binomial. When financial, legal, and/or time constraints prevent the collection of voucher specimens or the use of advanced molecular technologies, arguably the “gold standards” for plant identification, alternative methods such as photography and morphological descriptions may still be able to assist identification. There are unknowns about the relative accuracies of these different techniques. This paper compares the efficacy of several methods to correctly identify plants across five separate site visits in the province of Manabi, Ecuador. Methods: Plants that were identified to genus-, and species-level accuracy during each of the five site visits were totaled, and the type of data (expert consultation, written, photographic, and morphological) leading to the identification noted. Percentage accuracy was calculated as the number of unambiguous identifications to Latin binomial divided by the total number of common plant names recorded for each site visit. Results: Ninety-six common plant names were recorded across the five site visits, while each individual visit yielded information about 26-54 plants, reflecting significant overlap. In addition to interview data, site visit 4 uniquely collected additional photographic (34 plants) and morphological data (12 plants). Photographs were more effective in aiding identification to both genus (12) and species (4) than morphological data (4 genus and 0 species identifications). Percentage accuracy for the first four site visits ranged from 27-36%; site visit 5 yielded 91% accuracy, but only when considering a limited subset of the plants. Conclusions: Photographic, and morphological data can aid identification of medicinal plant species to Latin binomial when time, money and/or collection permits are lacking, but should not be considered reliable substitutes for plant voucher specimens or advanced molecular technologies.