Paraboea wenshanensis, a new species of Gesneriaceae from Yunnan, China

Abstract Paraboea wenshanensis is a new species of Gesneriaceae from Yunnan, China and is described and illustrated here. It is morphologically similar to P. angustifolia, P. martinii and P. glutinosa, but the congeners of this new taxon can be distinguished by several salient characters. A description of P. wenshanensis, together with illustrations and photographs, a distribution map and conservation assessment are presented.


Introduction
Southern and south-western China has extensive areas of karst topography (Chenet al. 2008) so that seed plants in this region show extreme diversity and are endemic on alkalescent limestone substrates (Xu 1993), a typical example being Gesneriaceae (Fang et al. 1995, Wang et al. 1998, Li and Wang 2004, Wei et al. 2010, Ai et al. 2015.
Paraboea (C.B. Clarke) Ridley has recently been redefined to accommodate Phylloboea Benth and Trisepalum C.B. Clarke (Middleton et al. 2010, Puglisi et al. 2011, distributed from south to southwest China, Indo-China Peninsula to Malaysia, Indonesia and the Philippines (Burtt 1984, Xu and Burtt 1991, Xu et al. 2008, Triboun and Middleton 2012. Many new taxa of this genus have been discovered and published in recent years (Chen et al. 2008, Kiew 2010, Wei et al. 2010, Chen et al. 2012, Wen et al. 2013, Wen and Wei 2016. Paraboea is restricted to Asia and includes about 130+ species (Weber 2004, Wen andWei 2016).
In 2009, one of the authors (WF) encountered a Paraboea species with last year's fruits when collecting plants specimens endemic to karst landforms in Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province. Then, in the course of floristic surveys in Wenshan National Nature Reserve between 2012 and 2014, the same species was again collected by the authors. After thorough comparisons of diagnostic morphological and anatomical features of similar taxa from China, Vietnam and Thailand (Barnett 1961, Wang 1990, 1998, Xu and Burtt 1991, Xu 1994, Pham-Hoang 2000, Burtt 2001, Li and Wang 2004, Xu et al. 2008, it was concluded that it was a species new to science and thus it is described and illustrated here.

Material and methods
Measurements and morphological character assessments of the putative new species were undertaken and described using specimens worked on by the current authors and living material observed in the field and at the Gesneriad Conservation Centre of China. All available specimens of Paraboea stored in the following herbaria in China, Vietnam, the United States and the United Kingdom were examined (codes according to Thiers 2015): E, GH, HN, IBK, K, KUN, MO, PE, PH, US and VNMN. In addition, images of other type specimens were obtained from Tropicos (http://www.tropicos.org), JSTOR Global Plants (http://plants.jstor.org) and the International Plant Names Index (http://www.ipni.org). All morphological characters were studied under dissecting microscopes and are described using the terminology presented by Wang et al. (1998).
Conservation status. Current information for this new species is only known from very few collections and details on the size of the population are known in Wenshan Nature Reserve, where the plants' protected status is guaranteed. Based on five careful field investigations in the past years, this species appears to be locally abundant. Considering that not enough is known about the population, it is proposed that Paraboea wenshanensis should currently be classed as data deficient (DD) (IUCN 2016).
Notes. The geographical distributions of P. wenshanensis and its similar species are identified in Map 1.