Figure 4 from: Zhu XX, Zheng HL, Wang J, Gao YQ, Ma JS (2019) Taxonomic studies on the genus Isotrema (Aristolochiaceae) from China: I. I. cangshanense, a new species from Yunnan. PhytoKeys 134: 115-124. https://doi.org/10.3897/phytokeys.134.37243 - Zhu, Xin Xin (2019)