The Use of BUse Value^: Quantifying Importance in Ethnobotany JASMINE ZENDERLAND 1 ,ROBBIE HART* ,2 ,RAINER W. BUSSMANN 3 , NAREL Y. PANIAGUA ZAMBRANA 3 ,SHALVA SIKHARULIDZE 3 ,ZAAL KIKVIDZE 3 , DAVID KIKODZE 3 ,DAVID TCHELIDZE 3 ,MANANA KHUTSISHVILI 3 , AND KETEVAN BATSATSASHVILI 4 1 Humboldt State University, 1 Harpst Street Arcata CA 95521 USA 2 Missouri Botanical Garden, 4344 Shaw Blvd St. Louis MO 63110 USA 3 Institute of Botany and Bakuriani Alpine Botanical Garden, Department of Ethnobotany, Ilia State University, Botanikuri St. 1 0105 Tbilisi Georgia 4 Institute of Ecology, Ilia State University, 5 Cholokasvili Ave 0162 Tbilisi Georgia *Corresponding author; e-mail: robbie.hart@mobot.org The Use of BUse Value^: Quantifying Importance in Ethnobotany. Use value (UV) is an index widely used to quantify the relative importance of useful plants. It combines the frequency with which a species is mentioned with the number of uses mentioned per species, and is often used to highlight prominent species of interest. However, high-UV species are often disproportionately cultivated species, with wild-collected plants ranking lower. To better understand this pattern, and to determine if it is present in the broader ethnobotanical literature, we reviewed an array of papers with results on UV and cultivation status, and we analyzed in depth data from two large ethnobotanical studies in the Republic of Georgia in the Caucasus. In addition to looking for differences in UV by cultivation status, we compared the two best-populated categories of use (medicinal and food uses) and the components of UV (relative frequency of citation and number of uses mentioned per species). We found that UV was higher in cultivated plants than wild plants in both the Caucasus datasets and the 17 studies overall. Medicinal plants did not exhibit this trend, as medicinal wild plants had marginally higher UV than medicinal cultivated plants. Relative frequency of citation had a substantial effect on UV, in contrast to number of uses mentioned for a given plant. In sum, UV seems subject to some obscured biases which are important to consider in the context of each study. Key Words: Quantitative ethnobotany, importance index, use value, cultivation, wild collection. Introduction Ethnobotanical studies often seek to identify and evaluate the plant species that are most important to a given culture (Albuquerque et al. 2006; Dudney et al. 2015). Beyond the direct relevance to understand- ing cultural value systems, in order to draw broader conclusions about ethnobotanical knowledge across cultures, we must be able to measure ethnobotanical knowledge in a consistent way (Reyes-Garcia et al. 2007; Turner 1988). The relative ethnobotanical importance of plants is also pertinent to conserva- tion biology (under the presumption that the most important species may be subjected to the greatest harvesting pressure) and may inform new drug dis- covery from ethnobotanically useful species (Albuquerque et al. 2006; Byg and Balslev 2001; Morvin Yabesh et al. 2014). With these and other benefits in mind, quantitative importance metrics have been utilized more frequently in the field of ethnobotany in the past 30 years (Phillips 1996). These metrics are most valuable when clearly un- derstood (Hoffman and Gallaher 2007) and when 1 Received 1 February 2019; accepted 2 October 2019; published online ___________ Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12231-019- 09480-1) contains supplementary material, which is avail- able to authorized users. Economic Botany, XX(X), 2019, pp. 1–11 © 2019, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A.