Assessing Red List categories to a Korean endangered species based on IUCN criteria - Hanabusaya asiatica (Nakai) Nakai-

ABSTRACT : The conservation status of an endemic perennial herb, Hanabusaya asiatica (Nakai) Nakai (Cam-panulaceae) was determined by applying the IUCN risk assessment criteria from our field study and availablespecimen data. Also, the GIS technology was used to develop a species distribution map to calculate the extentof occurrence (EOO) and area of occupancy (AOO) for the taxon. After two years of continuous field studies,269 mature individuals were found in four localities in 2011, while 216 mature individuals were confirmed inthree localities in 2012. Based on the following data, such as EOO (2,742 km 2 ), AOO (76 km 2 ) and estimatedpopulation size of mature individuals, the taxon, which is known as 20 localities in Korean peninsula, is eval-uated as the category of Endangered (EN). A major difficulty in application of IUCN criteria to Korean rareplants were the lack of essential biological information and understanding the correct knowledge of the IUCNcriteria in previous Korean studies. Sound conclusions regarding the conservation status of individual speciesrequire more intensive population studies, observations, and applying IUCN assessment procedures correctly.