A taxonomic revision of Ligustrum (Oleaceae) in Korea

A taxonomic revision of Korean Ligustrum species is presented based on critical observations of wild populations and herbarium specimens. Species delimitations were re-evaluated on the basis of morphological characters, such as plant height, texture and shape of leaf, shape of inflorescence, shape of drupe and seed, and texture of endocarp. From the results, L. leucanthum (= L. acutissimum), being recorded in Korea, is excluded from the Korean flora because it comes from misidentifications of the herbarium specimen, whose identity is L. obtusifolium. We also treated L.obtusifolium subsp. suave and L. obtusifolium subsp. microphyllum as synonyms of L.obtusifolium. Ligustrum quihoui var. latifolium is placed into synonym of L. quihoui. In addition, the record of L. ovalifolium from Korea has proved to be a misidentification of herbarium specimens, the correct identity of which is L. salicinum. Consequently, we recognized the following six Ligustrum species in Korea: L. japonicum, L. lucidum, L. quihoui, L. salicinum, L. foliosum, and L. obtusifolium. Photographs and a key to six species of Ligustrum were provided in addition to complete descriptions including information on nomenclatural types, synonyms, and taxonomic notes.