Ethnobotany studies the complex relationships between plants and people. The University of Colorado Herbarium houses one ethnobotanical collection that was assembled by Dr. Robert Bye, who studied the availability and distribution of plants used for medicinal and cultural purposes in Mexico.
Bye purchased hundreds of plant samples from Mexican markets, recording their uses, methods of preparation, local names, sources, and price. The specimens were dried, microwaved, or otherwise preserved to maintain their condition for long-term storage. In the Herbarium, they are stored in plastic bags in dry, dark cabinets to minimize deterioration.
The top image shows wood chips from a tree in the pea family called palo brasil by the local people (Haematoxylon brasiletto). This tree is quite common in dry parts of western Mexico. According to the seller in the market, these chips are to be soaked in water and drunk as a tea to comfort sad children and relieve heart ailments. Other uses include improving circulation, treating arthritis and depression, washing wounds, and dyeing cotton red.
The image at right displays a bundle of flowering stems of "yerbanis," (Tagetes lucida), a plant in the sunflower family, that was collected by Tarahumara Indians to be made into a tea to treat colds. One plant species may be used by different people for many different purposes. This species is also used by various cultural groups for stomach ailments, for flavoring food, and as an element in religious rituals. Modern chemical analyses of the plant have found that it has antifungal and antibacterial properties.