The neighbor-joining (NJ) tree, based on ITS sequence data. Carpinus mollicoma, C. rupestris and C. tschonoskii as related species; P1–P4 are samples of C. polyneura from Hupingshan (HPS), Shimen, Hunan, China; P5–P7 are samples of C. polyneura from Dapanshan (DPS), Panan, Zhejiang, China; P8 is a sample of C. polyneura from Liujiaping (LJP), Wufeng, Hubei, China; P9 is a sample of C. polyneura from Caoyuan (CY), Longli, Guizhou, China; D1–D3 are samples of C. dayongina from Tianmenshan (TMS), Zhangjiajie, Hunan, China. The numbers above the branch are bootstrap values (%), and the numbers below the branch are branch length.