title: Analysis of traditional knowledge in medicinal plants used by Yuan in Thailand.
abstract: BACKGROUND
  We studied traditional knowledge of medicinal plants use of the Yuan in northern Thailand, documenting and analysing traditional medical practices and its trend in the younger generations.
  
  
  OBJECTIVE
  To providing useful information for appropriate and sustainable management under the urbanization and other developments and use of natural resources in their communities. In addition, traditional medicinal plant used, and knowledge that leads to discovery of new medicines can be promoted.
  
  
  METHODS
  Traditional medicinal plant knowledge of the Yuan in Lamphun province was studied from October 2009 through September 2011 in order to determine the important medicinal plant species and dominant use-categories in 5 villages. In each village, questionnaire interviews about medicinal plants uses were applied to 30 informants (5 informants per each of six stratified age groups). The relative importance of plant species was captured by calculation of use value (UV). Likewise, the dominant use-categories were determined by calculation of the informant agreement ratio (IAR). Correlations between informants' age and number of medicinal plants known by them were determined with the coefficient of determination (R(2)).
  
  
  RESULTS
  A total of 93 medicinal plant species in 82 genera and 49 families were recorded in the five villages. The most important species of medicinal plants were Aloe vera (L.) Burm.f., Andrographis paniculata Ness, Chromolaena odorata (L.) R.M.King and H.Rob., Jatropha podagrica Hook., and Thunbergia laurifolia Lindl. which had UVs of 1.02, 1.01, 0.75, 0.71, and 0.65, respectively. Likewise, the most dominant use-categories were injuries, which accounted for 0.91 of the IAR. The age of informants and medicinal plants reported by each of them were positively correlated (R(2)=0.96, p<0.01).
  
  
  CONCLUSIONS
  Most of the Yuan's traditional medicinal plant knowledge is used for treating basic ailments. However we should be concerned that there is an imminent danger that it will be lost in the near future because their lifestyle was changing.
authors.affiliation: Chiang Mai University, Department of Biology, Faculty of Science, Meung, Chiang Mai 50200, Thailand. aungkanainta@hotmail.com
authors.forename: Angkhana
authors.initials: A
authors.lastname: Inta
authors.forename: Paritat
authors.initials: P
authors.lastname: Trisonthi
authors.forename: Chusie
authors.initials: C
authors.lastname: Trisonthi
mesh_terms: D019448:Ethnobotany; D020834:Ethnopharmacology; D007722:Health Knowledge, Attitudes, Practice / Q000208:ethnology*; D006801:Humans; D008518:Medicine, East Asian Traditional; D028321:Plant Preparations / Q000627:therapeutic use; D010946:Plants, Medicinal / Q000145:classification; D013785:Thailand
chemical_list: D028321:Plant Preparations
keywords: Ethnobotany; Informant agreement ratio (IAR); Northern Thai; Traditional medicinal plants; Use value (UV)