Novelties in Begonia sect. Coelocentrum: B. longgangensis and B. ferox from limestone areas in Guangxi, China

Abstract

BackgroundThe spectacular karst limestone landscape in Guangxi harbors high-level diversity and endemism of Begonia species, especially those of sect. Coelocentrum. In continuation of our studies in this area, we report the discovery of two attractive new species from southwestern Guangxi: Begonia longgangensis and B. ferox.ResultsBegonia longgangensis resembles B. liuyanii, also from Longgang Nature Reserve, in the broadly ovate to suborbicular leaf blade, differing by the much smaller leaves, subglabrous leaf surface, pink flowers, dichasial cymes and the remarkably long stolons sent out from rhizomes. Unexpectedly, both diploid (2n = 30) and triploid counts (2n = 45) were observed in plants collected from the type locality. Begonia ferox probably has the most prominent bullate leaves for the genus. In this aspect, it is similar to B. nahangensis reported from northern Vietnam recently, but is readily distinguishable by the ovate, chartaceous leaves with an acuminate apex; tomentose peduncle not exceeding petioles; and the much larger stature in vegetative parts. A diploid count of 2n = 30 was determined for this unique new species.ConclusionsAll available data support the recognition of the two new species. Begonia longgangensis has remarkably long stolons and B. ferox is characterized by the prominent bullate leaves. Line drawings, color plates and comparisons are provided to aid in identification of the novelties.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-54-44) contains supplementary material, which is available to authorized users.

Four new species of Begonia (Begoniaceae) from Vietnam: B. abbreviata, B. calciphila, B. sphenantheroides and B. tamdaoensis

“…4F). Chromosome cytology:-The Asian section Coelocentrum consistently shows the chromosome number of 2n = 30 (Peng et al 2012(Peng et al , 2013(Peng et al , 2014a, with the exception of some probable intraspecific autotriploid individuals with 2n = 45 in B. longgangensis C.- I Peng & Yan Liu (2013: 54-44: 2) (Peng et al 2013). In this study, the diploid count of 2n = 30 was documented for Begonia calciphila (Fig.…”

Phylogenetic analyses of Begonia sect. Coelocentrum and allied limestone species of China shed light on the evolution of Sino-Vietnamese karst flora

“…In the past decade renewed interest and ongoing explorations to under-collected regions have resulted in the description of more than 140 new species in Asia (e.g., de Wilde et al2011; Thomas et al2011b; Averyanov and Nguyen2012; Peng et al20122013). Traditionally these Asian species are classified into 22 sections of highly unequal sizes (Doorenbos et al1998; Shui et al2002; Gu2007; Hughes and Pullan2007; Kiew2005; Thomas et al2011a), with eight of the largest sections: sect.…”

“…Based on recent treatment of Begoniaceae in the Flora of China (Gu et al2007) and subsequent studies (Liu et al2007; Peng et al20072008a,b20122013; Li et al2008; Shui2007; Wei et al2007), ca. 170 species of Begonia assigned to 9 (Shui et al2002) or 7 (Gu2007) sections are currently known from continental China, with sect.…”

Two new species of

“…are one of the most prominent groups, comprising ca. 55 rhizomatous species characterized by parietal placentation (Doorenbos et al 1998;Ku 1999;Gu et al 2007;Liu et al 2007;Peng et al 2007Peng et al , 2008Peng et al , 2013Averyanov and Nguyen 2012;Ku et al 2008) which is rarely seen in other Asian Begonia (Thomas et al 2011).…”

“…(e.g., Lin et al 2013), Begonia L. (e.g., Averyanov and Nguyen 2012;Peng et al 2012;Peng et al 2013), Elatostema J.R. Forst. and G. Forst.…”