“The Importance of a Rose”: Evaluating the Cultural Significance of Plants in Thompson and Lillooet Interior Salish

The evaluation of the cultural significance of plants in ethnobotanical studies is an essential step in various types of investigations, including research on lexical retention of plant names in diverging languages, on trade and material exchange between groups, on subsistence strategies, and on folk classification. An index of cultural significance was developed, based on ethnobotanical data on Thompson and Lillooet, two Interior Salish groups of British Columbia. For a given plant taxon, the index is a composite of a wide variety of potential applications of a plant, ranked according to the contribution of each separate application to survival in traditional cultures, together with estimates of intensity and exclusivity of use for each. Example calculations of the derivation of the index are provided, as well as a summary of calculations for more than 500 plant species from Thompson and Lillooet territories. The index has some limitations, but overall it seems to provide a meaningful and valid assessment of the relative importance of a plant taxon in Thompson and Lillooet.