Revisiting Rosa maximowicziana (Rosaceae) in Korea: Implications for Red List assessment and development of conservation strategies

Rosa maximowicziana (Rosaceae), a wild rose species native to Korea, represents a unique lineage occurring in cool temperate and hemiboreal forests. Due to its limited distribution and lack of taxonomic information, R. maximowicziana has been poorly understood in South Korea. Through extensive herbarium research and field investigations, we investigated its distribution, morphology, phenology, and population ecology in South Korea. We found that R. maximowicziana inhabits thickets and forests edges in cool temperate regions with wet soils, which are highly restricted and sparsely scattered across the northern part of South Korea. A total of 22 populations were identified and subsequently evaluated, all of which are severely fragmented and extremely small in size and area. In addition, low genetic diversity resulting from asexual reproduction, genetic swamping through introgressive hybridization with more widely distributed Rosa multiflora, and ongoing anthropogenic threats further endanger this species. Given these newly compiled findings, we highlight the need for urgent conservation and suggest a Regional or National Red List assessment to provide appropriate conservation strategies for R. maximowicziana in South Korea.