Three new species of Paraboea (Gesneriaceae) from limestone karsts of China based on morphological and molecular evidence

Wei-Bin Xu,Yan Liu,Meng-Qi Han,Jing Guo,Bo Pan,Kuo-Fang Chung

doi:10.1186/s40529-017-0207-5

Abstract

BackgroundThe limestone karsts of Southeast Asia and South China are a major biodiversity hotspot of global terrestrial biomes. With more than 130 described species, Paraboea has become one of the most characteristic plant groups in the Southeast Asian limestone flora. During the course of extensive field work on the limestone formations of southern and southwestern China, three unknown species of Paraboea were collected.ResultsMolecular phylogenetic analyses based on nuclear ITS and chloroplast trnL-F sequences strongly confirm the placements of the three new species in Paraboea sensu Puglisi et al. (Taxon 65:277–292. https://doi.org/10.12705/652.5, 2016). Moreover, these three novelties can be distinguished from known Paraboea species with distinct morphological characters, further supporting their recognition as new species.ConclusionsWith the support of detailed morphological studies and molecular phylogenetic analyses, Paraboea dushanensis, P. sinovietnamica and P. xiangguiensis are recognized as three species new to science.

Highlights

The limestone karsts of Southeast Asia and South China are a major biodiversity hotspot of global terrestrial biomes
Samples of the three new species (Paraboea dushanensis, P. sinovietnamica and P. xiangguiensis) are shown as distinct clades grouped within Paraboea sensu Puglisi et al (2016) with strongest support values (BS = 100%, posterior probability (PP) = 1.00), ascertaining their recognition as distinct species of Paraboea
Multiple samples identified as Paraboea dushanensis, P. xiangguiensis, and P. sinovietnamica are all monophyletic (BS = 98, 100, 70%, PP = 1.00, 1.00, 0.96), and each of these three new species is placed as sister group of its morphologically most similar congener [i.e., P. velutina (W.T.Wang & C.Z.Gao) B.L.Burtt, Paraboea crassifolia (Hemsl.) B.L.Burtt, P. guilinensis L.Xu & Y.G.Wei, and P. sinensis (Oliv.) B.L.Burtt] with strong support (Fig. 1)

Summary

Introduction

The limestone karsts of Southeast Asia and South China are a major biodiversity hotspot of global terrestrial biomes. More than 30 new species have been described since the revision by Xu et al (2008), almost all narrowly distributed endemic from limestone karsts (Chen et al 2008, 2012; Kiew 2010; Triboun and Middleton 2012, 2015; Xu et al 2012a; Triboun 2013; Wen et al 2013; Puglisi et al 2015; Guo et al 2016; Wen and Wei 2016). Because a great proportion of Asian limestone karsts remain unexplored or underexplored, it is fully expected that additional new species of Paraboea will be unearthed given that further field investigations and herbarium work are conducted (Puglisi et al 2015).

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Conclusion