Riparian ecosystem services: Akimel O’otham ethnomedicine use of plants in the Salt River, Phoenix, AZ

Background/Question/Methods

The National Center for Complementary and Alternative Medicine (CAM) is the leading federal agency on CAM research. According to sequential National Health Interview Surveys, CAM use, which includes Traditional Indigenous Medicine, has increased nation wide. The population of the Phoenix metro area has increased over the last century, with associated increases in Indigenous people, Chicano/a, and Asian populations, the major users of CAM. Riparian ecosystems are diverse in plant species, and urban growth has led to portions of the Salt River being restored in efforts to increase the range of ecosystem services it provides. The riparian zone provides habitat for many native and introduced plants, but current management involves clearing the introduced from restoration sites. This led to our question: Does the number of potential medicinal and food sources (ecosystem services) differ between native and introduced plants in the Salt River riparian zone? We directly inventoried study sites for plant composition and also queried SEINet (a regional plant database) to determine the identity of plants growing along the river. To determine medicinal uses (particularly ethnomedicine of regional indigenous Akimel O’otham (AO) people) we queried several ethnobotany/medicine databases, and prior information from AO elders with plant knowledge.

Results/Conclusions

Of the 52 woody plants in the urban Salt River riparian zone, 40 are native and 12 are introduced. A total of 162 CAM uses from 29 plants were found. A total of 26 plants provide a potential source of food, with 7 of these being introduced plants. 17 plants had ≥1 AO CAM use, which totaled 62 AO CAM treatment purposes. Shegoi (Larrea tridentata) had the most AO ethnomedicine purposes with 17 recorded. Kui (Prosopis velutina) had the next most at 11, followed by U’us kokomagῐ (Pluchea sericea) with 7. Only one introduced plant, Maamsh (Ricunis communis) had any AO CAM use (laxative, analgesic, cathartic, and derma aid), although 9 of the introduced plant species had ≥1 CAM use. The plant with the most CAM potential was the introduced S-ee-ekagkam (Melia azederach), with 20 medicinal applications, but none recognized by AO overall. We conclude that native and introduced woody plants along the Salt River do provide significant potential for traditional medicinal uses and for wild food consumption.  Consideration of the plants’ ethno functional roles could be used as a basis to determine whether or not to weed plants from restoration sites.