Local knowledge of medicinal plants in sub-ethnic Batak Simalungun of North Sumatra, Indonesia

Simalungun of North Sumatra was conducted, using an ethnobotanical approach. The sample consisted of 8 key informants and 32 general respondents, who were grouped into two, namely those who were 30-50 years old and>50 years old. Data were analyzed both qualitatively by descriptive statistics and quantitatively by calculating the index of cultural significance (ICS) and the use value (UVs). It was found that 239 species (170 genera, 70 families) of medicinal plants were used to cure 18 kinds ofnatural diseases and 2 kinds of supra natural diseases. Almost half of those plants (119 species) had leaves used as medicines. Among the diseases, gastrointestinal disorders had the highest number of medicinal plants used (72 species), followed by fever (64 species), and fractures (41 species). It seemd that younger generation had lost their knowledge in the medicinal plants because their knowledge of medicinal plants (48.19 ± 8.35 species) was lower than the that of older generation (170.19 ± 18.38 species), while our key informants had the highest knowledge of medicinal plants among respondents (202.00 ± 12.32 species)