New Callicarpa (Lamiaceae) taxa: Two species and a natural hybrid from Hahajima Island, Ogasawara Islands, Japan

Two newly identified species of Callicarpa (Lamiaceae), C. boninensis and C. hahajimensis , along with a new natural hybrid, C . × chibusensis are described, all of which were identified on Hahajima Island, Ogasawara Islands, Japan. A comprehensive key to Callicarpa species in the Ogasawara Islands is also provided. Callicarpa boninensis , morphologically most similar to C. subpubescens , is distinguished by persistent stellate hairs on mature leaves and elongated petioles. Callicarpa hahajimensis , resembling C. parvifolia in the Chichijima Islands, differs in its reduced stellate hair density on both leaf surfaces and thinner leaves. Callicarpa × chibusensis , considered a natural hybrid between C. subpubescens and C. boninensis , is characterized by intermediate stellate hair densities—higher than in C. subpubescens but lower than in C. boninensis —on both leaf surfaces, smaller leaves than those of C. subpubescens , and a distinct flowering phenology relative to that of C. boninensis .