102 urn:lsid:arphahub.com:pub:73abe0ce-d97c-5d7c-bee5-b8e6e6fe6a17 ARPHA Preprints preprints Pensoft Publishers 10.3897/arphapreprints.e73692 73692 Research Article Angiospermae Aristolochiaceae Taxonomy Asia Isotrema putalengense, a new species of Aristolochiaceae from northern Vietnam and two new combinations in Isotrema Nguyen Quoc Binh binhzing@gmail.com 1 Nguyen Hieu Cuong 2 Tran Duc Binh https://orcid.org/0000-0001-6658-0739 3 Nguyen Phuong Hanh 3 Luu Hong Truong hongtruongluu@gmail.com https://orcid.org/0000-0002-7036-7081 4 5 Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, Hanoi, Vietnam Vietnam National Museum of Nature, Vietnam Academy of Science and Technology Hanoi Vietnam Southern Institute of Ecology, Vietnam Academy of Science and Technology, Ho Chi Minh, Vietnam Southern Institute of Ecology, Vietnam Academy of Science and Technology Ho Chi Minh Vietnam Institute of Ecology and Biological Resource, Vietnam Academy of Science and Technology, Hanoi, Vietnam Institute of Ecology and Biological Resource, Vietnam Academy of Science and Technology Hanoi Vietnam Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam Graduate University of Science and Technology, Vietnam Academy of Science and Technology Hanoi Vietnam Southern Institute of Ecology Vietnam Academy of Science and Technology, Ho Chi Minh, Vietnam Southern Institute of Ecology Vietnam Academy of Science and Technology Ho Chi Minh Vietnam

Corresponding authors: Quoc Binh Nguyen (binhzing@gmail.com), Hong Truong Luu (hongtruongluu@gmail.com).

Academic editor:

2021 30 08 2021 1 552896B6-DD92-5D8F-8689-97D48408789A 30 08 2021 30 08 2021 Quoc Binh Nguyen, Hieu Cuong Nguyen, Duc Binh Tran, Phuong Hanh Nguyen, Hong Truong Luu This is an open access preprint distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Isotrema putalengense Luu, Q.B.Nguyen & H.C.Nguyen is described as a new species from northern Vietnam. It looks most morphologically like I. wardianum but is distinguishable by a combination of different leafy and floral characters. Morphological comparison between the new plant and closest species is provided. In addition, combinations of two recently described Aristolochia species are made, namely Isotrema vuquangense (T.V.Do) Luu, Q.B.Nguyen & H.C.Nguyen and Isotrema yachangense (B.G.Huang, Yan Liu & Y.S.Huang) Luu, Q.B.Nguyen & H.C.Nguyen.