A taxonomic revision of Boehmeria (Urticaceae) in Korea

This study presents a taxonomic revision of Korean Boehmeria, which has been difficult to classify owing to variation in leaf morphology. Based on protologues and type specimens, morphological and micromorphological analyses were conducted for taxon identification, along with multi-year field surveys and observations of dried herbarium specimens. Characteristics related to habit, stem, phyllotaxy, stipule, abaxial leaf surface, inflorescence, perianth of staminate flowers, glomerules of the infructescence, and achene were taxonomically significant. Furthermore, B. nivea var. nipononivea was clearly differentiated from B. nivea by leaf shape; midvein on the abaxial surface; and trichomes on the stems, perianth of staminate flowers, and achenes. Accordingly, this taxon was elevated to species rank as B. nipononivea. Four species previously regarded as Korean endemics—B. hirtella, B. nakaiana, B. taquetii, and B. quelpaertensis—were revealed to be distributed in Japan. Among these, B. nakaiana and B. taquetii were treated as synonyms of B. sieboldiana. Morphological analyses supported the application of Wang’s classification system to Korean Boehmeria. The series Sieboldianae within sect. Duretia was newly combined. In conclusion, Korean Boehmeria comprises 13 species in two sections and three series. For each species, descriptions, taxonomic notes, photographs, distribution information, and keys are provided.