A–C Isotrema cangshanense X.X.Zhu, H.L.Zheng & J.S.Ma, sp. nov. A leaves B flower (lateral view) C longitudinal section of flower (showing the inside structure) D–F Isotrema utriforme (S. M. Hwang) X. X. Zhu, S. Liao & J. S. Ma D leaves E flower (lateral view) F longitudinal section of flower (showing the inside structure) G–I I. forrestianum (J. S. Ma) X. X. Zhu, S. Liao & J. S. Ma G leaves H flower (lateral view) I longitudinal section of flower (showing the inside structure) J–L I. obliquum (S. M. Hwang) X. X. Zhu, S. Liao & J. S. Ma J leaves K flower (lateral view) L longitudinal section of flower (showing the inside structure). A–C, G–I Photographed by Xinxin Zhu D–F photographed by Lei Cai; J–L photographed by Yuan Wang.