First Record of an Alien Plant Species, Dentella repens (Rubiaceae) from Japan

Abstract

We collected an alien plant, Dentella repens (L.) J.R.Forst. & G.Forst. (Rubiaceae) for the first time from the northern part of Iriomote Island, Okinawa, Japan in 2020. It is a new record of the species and the genus Dentella from the country. Since the first record in 2020, the plant has been found steadily growing at one site in a village near the northern shore of the island. We observed the morphology of the collected materials in detail under a stereomicroscope and the characteristics were generally consistent with the descriptions of the species in previous studies. The features of hairs on the corolla and calyx lobes are new additional information for the species.