Checklist to the Elatostema (Urticaceae) of Vietnam including 19 new records, ten new combinations, two new names and four new synonyms

Long-Fei Fu; Alex Monro; Truong Van Do; Maxim S Nuraliev; Leonid V Averyanov; Fang Wen; Zi-Bing Xin; Tatiana V Maisak; Andrey N Kuznetsov; Svetlana P Kuznetsova; Khang Sinh Nguyen; Yi-Gang Wei

doi:10.7717/peerj.6188

Checklist to the Elatostema (Urticaceae) of Vietnam including 19 new records, ten new combinations, two new names and four new synonyms

PeerJ. 2019 Jan 10:7:e6188. doi: 10.7717/peerj.6188. eCollection 2019.

Authors

Long-Fei Fu¹, Alex Monro², Truong Van Do³, Maxim S Nuraliev^{4

5}, Leonid V Averyanov⁶, Fang Wen¹, Zi-Bing Xin¹, Tatiana V Maisak⁶, Andrey N Kuznetsov^{4

7}, Svetlana P Kuznetsova⁴, Khang Sinh Nguyen⁸, Yi-Gang Wei¹

Affiliations

¹ Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin, China.
² Identification and Naming Department, Herbarium, Royal Botanic Gardens, Kew, London, United Kingdom.
³ Department of Biology, Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
⁴ Joint Russian-Vietnamese Tropical Scientific and Technological Center, Hanoi, Vietnam.
⁵ Department of Higher Plants, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia.
⁶ Komarov Botanical Institute of the Russian Academy of Sciences, St Petersburg, Russia.
⁷ Severtsov Institute of Ecology and Evolution Problems of the Russian Academy of Sciences, Moscow, Russia.
⁸ Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Hanoi, Vietnam.

Abstract

Elatostema (Urticaceae) comprises several hundred herbaceous species distributed in tropical and subtropical Africa, Asia, Australia and Oceania. The greatest species richness occurs on limestone karst in Southeast Asia. Taxonomic revisions of Elatostema are largely out of date and contradict each other with respect to the delimitation of Elatostema and Pellionia. Most herbaria in SE Asia and worldwide contain significant amounts of unidentified material. As part of a broader revision of Elatostema in SE Asia, we present an updated checklist for Vietnam based on field visits, a review of specimens in herbaria worldwide, a review of type material and nomenclature. We recognize 77 taxa (75 species and two infraspecific taxa) of Elatostema in Vietnam, 23 of which were previously ascribed to Pellionia. Nineteen of these are new records for the country, i.e., E. attenuatoides, E. austrosinense, E. backeri, E. brunneinerve, E. crassiusculum, E. crenatum, E. fengshanense, E. glochidioides, E. malacotrichum, E. nanchuanense, E. oblongifolium, E. obtusum, E. oppositum, E. pergameneum, E. prunifolium, E. pseudolongipes, E. pycnodontum, E. salvinioides and E. xichouense. We place E. baviensis in synonymy of E. platyphyllum, E. colaniae in synonymy of E. myrtillus, P. macroceras in synonymy of E. hookerianum, and P. tetramera in synonymy of E. dissectum for the first time. Fourteen taxa (18% of all the recognized taxa) are endemic to Vietnam, which makes Elatostema one of the richest genera for endemic species in this country; this level of endemism is comparable to levels observed in Orchidaceae. Our checklist suggests that the highest diversity and endemism of Elatostema occurs in northern Vietnam, and that there is the greatest floristic similarity of northern Vietnam to SW China. The relationship among floristic regions is also investigated. We could find no records of Elatostema for 33 out of 63 provincial units of Vietnam, including all the southernmost provinces. We propose that further studies on the diversity of Elatostema in central and southern Vietnam are severely needed.

Keywords: Begonia; Elatostemateae; Flora of Vietnam; Indochina; Karst; Lectotypification; Limestone; Orchidaceae; Pellionia; Taxonomy.

Grants and funding

This work was supported by the National Natural Science Foundation of China (No. 31160039 and 31570307), the Russian Foundation for Basic Research (grant 18-54-54005 Viet-a) and the Federal Agency for Scientific Organizations Program for Bioresource Collections, Russia (0126-2017-0005). The work of Maxim S. Nuraliev was carried out in accordance to Government order for the Lomonosov Moscow State University (project No. AAAA-A16-116021660105-3). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.