This ethnobotanical field study documents local knowledge on medicinal plant use in two localities on different altitudes in the northern Peruvian Andes. The research area in the biologically diverse yet scarcely investigated Marañón valley shows a variety of vegetation forms, ranging from inter-Andean dry forest to Andean cloud forest and tropical high altitude grassland. Local populations consist of mestizo communities with partial cultural heritage from the Chachapoya, a pre-Inca Amerindian ethnic group with a long and elaborate healing tradition.
Semi-structured interviews with 120 informants, from whom 21 were considered as local healers, yielded a total of 3035 use reports. In all, 279 medicinal plant species were collected and identified, and their local names, medicinal uses and applications recorded.
The highest number of use reports referred to gastrointestinal diseases, nerves, urological and respiratory problems; the most often used botanical families included Asteraceae, Fabaceae, Solanaceae, Lamiaceae and Rutaceae. About one third of the medicinal plant species were not native to the Andes, among them many Lamiaceae, Fabaceae and Rutaceae. Three of the six most often used plants were introduced species, namely eucalyptus, chamomile, and aloe vera. The most frequently used native ethnospecies were Cola de Caballo (Equisetum giganteum and E. cf. bogotense), Pie de Perro (Desmodium molliculum), and Matico (Piper spp.). In the majority of cases, aerial parts of medicinal plants were applied orally, as infusions or decoctions. Topical applications included cataplasms or rubbing with plant material; in some cases, plants were used for ritual healing ceremonies (limpias).
Local use of many of the medicinal plant species is supported by ethnopharmacological data. The two localities differ in medicinal plant use regarding the most frequently used species; this may be explained mainly by differences in availability due to different vegetation zones. The underlying cultural concepts for the use of local plant medicine include Andean cosmological beliefs in evil winds (aire), loss of soul or spirit through fright (susto), harms due to witchcraft (brujería) or envy of other people (envidia). Further, the hot-cold dichotomy of diseases and remedies suppositionally based on western humoral pathology is applied.
Knowledge on medicinal plant use is distributed along a continuum within the communities, with some persons of middle and old age salient by more extensive knowledge. However, many young individuals knew only few medicinal plant species; and generally a loss of knowledge was perceived by the majority of community members. Rapid changes in the societies presumably lead to erosion of local knowledge about medicinal plants; its valuation and documentation through the present work may contribute to its preservation.
Healers after arriving at the lagoons for collection of medicinal plants with attributed magical properties.