In northern Mexico, indigenous groups, like the Southern Tepehuans, keep a close relationship with their natural environment, including numerous species of plants. While formal schooling broadens their perspective and enhances professional opportunities outside of their communities, a study reports that it erodes their knowledge of many of these plants. To conserve regional flora and lore, education that values and includes traditional knowledge is key.
“Young Tepehuans often spend the whole day in school, so they do not help their parents with labour in the field, and traditional knowledge is primarily learned in the field,” explains ethnobotanist Raúl Narváez-Elizondo from the Instituto Politécnico Nacional in Durango, and first author of the paper published last September in Botanical Sciences.
There are several reasons to explain the waning bond between the younger generations of Tepehuans and their local flora. “[M]igration to urban areas, less use of their indigenous language, and a formal education received almost entirely in Spanish,” write Narváez-Elizondo and his colleagues in their publication.
Southern Tepehuans are an ethnic group living in the Mexican states of Durango, Nayarit, Sinaloa and Zacatecas, with the majority settled in the pine-oak forests in the Sierra Madre Occidental of southern Durango. The hills, valleys, and canyons of the Sierra harbour a high level of endemic plant species. And while Southern Tepehuans predominate in southern Durango, they share the area with other indigenous communities.

To examine the degree to which formal schooling determined how much young Tepehuans knew their local flora, the researchers gave a questionnaire to 162 informants, aged between 15–30 years old. The level of schooling varied among the informants. Some had received formal education in a city environment (urban), others had attended school within their communities (rural) and others had not received formal education (non-students). This last group spent more time in the field helping their parents, who are the “main diffusers of knowledge about wild edible plants,” write the authors in their publication.

From the 122 wild vascular plant species that the researchers had previously reported to be used by Southern Tepehuans as food, they selected 20 taxa representative of the different environments on the region to include in the questionnaire. Common species like Agave shrevei, and less known ones, such as Tripsacum dactyloides were considered. “We wanted to include it to have an idea of really how much the youngsters know,” says Narváez-Elizondo.
The informants saw images of each species and answered 10 questions about each one. Questions about the plant’s common names, knowledge about how the plant is cooked or eaten, and the source of such knowledge, were among those included. The answers were used to calculate a knowledge grade for each informant and the data was analysed to see the relationship between schooling and knowledge of wild edible plants.
The researchers found that “non-students have a higher traditional knowledge grade about edible plants than both rural and urban students.” They also found that rural and urban students had very similar grades in almost every aspect examined.
The group of researchers also found that people without formal education knew better in which season 14 out of the 20 species are available, and they showed greater knowledge about how the plants are eaten or cooked.

The opinion that informants had about consuming wild plants varied by species. In the case of the cactus Stenocereus queretaroensis, “the fruit is delicious, it is very difficult that somebody dislikes it,” says Narváez-Elizondo in the interview. Nonetheless, some informants thought of some plants merely as food for cattle or food that was eaten in the past.
In terms of familiarity, most informants were acquainted with three of the 20 species selected for the study: Arctostaphylos pungens, Agave shrevei and Leucaena leucocephala. Their popularity, however, is owed to different reasons.
In the case of the shrub Arctostaphylos pungens, its wide distribution in the region explains why informants are familiar with it, says Narváez-Elizondo, adding that its tiny reddish fruits are mainly eaten raw, though some people use them to prepare flavored water.
Leucaena leucocephala’s notoriety, on the other hand, might have more to do with human practices than with natural ubiquity. The tree, whose tender shoots are cooked, and seeds are commonly eaten raw or ground for salsa, grows in the low, warm areas of the mountains. Narváez-Elizondo says that its seeds are a common product, readily acquirable at higher elevations.
In addition to the 20 species selected by the researchers, informants wrote a list of other edible plants in the region that they were familiar with. The contributions from all informants resulted in a list with 48 additional plant species. Comparing the lists of the three groups, researchers found that “non-students provided the most extensive list of edible taxa,” further denoting their greater familiarity with the wild edible plants of the region.
The authors recommend promoting traditional ecological knowledge in formal education. They write that, in addition to theoretical content, incorporating ethnobotanical field activities, ethnogastronomic events and gardening projects would help “conserve and revitalize this valuable biocultural heritage.”
RESEARCH PAPER:
Narváez-Elizondo, R. E., González-Elizondo, M., Castro-Castro, A., González-Elizondo, M. S., Tena-Flores, J. A., & Chairez-Hernández, I. (2021). Comparison of traditional knowledge about edible plants among young Southern Tepehuans of Durango, Mexico. Botanical Sciences, 99(4), 834-849. https://doi.org/10.17129/botsci.2792
Updated February 8, 2023 for clarity.

Patrick Gibson graduated Cum Laude with a bachelor of science in biological sciences from Arkansas State University Campus Querétaro. He is interested in the different facets of botany and is happy to share his fascination for plants and science with others. Follow him on Twitter @pgibsonc.