Che-Wei Lin

Six new species of Begonia (Begoniaceae) from limestone areas in Northern Vietnam

BackgroundSpecies of Begonia are richly represented in limestone karst areas across the Sino-Vietnamese border. More than one hundred species were known, many of which were documented recently.ResultsIn continuation of our systematic studies of Asian Begonia, we report six species of Begonia that are unknown to science, namely B. caobangensis [sect. Platycentrum], B. circularis, B. melanobullata, B. langsonensis, B.locii and B. montaniformis [sect. Coelocentrum] from Northern Vietnam. Diagnostic features that separate them from morphologically allied species are provided. Somatic chromosome numbers were determined, which supports their placement in the respective sections. Foliar SEM microphotographs were taken and described.ConclusionA careful study of the literature, herbarium specimens and living plants, both in the wild and in cultivation in the experimental greenhouse, supports the recognition of the six new species, which are described and illustrated.

Two new species of Begonia, B. moneta and B. peridoticola (Begoniaceae) from Sabah, Malaysia

BackgroundMount Kinabalu, reknowned for its high biodiversity and endemism, is a National Park in the State of Sabah on the northern end of the island of Borneo. Every year many visit the higher part of the Kinabalu National Park, while most lowland forests in the Park are under-explored. Two unknown species of Begonia were collected from a peridotic (ultramafic) cliff in the Kinabalu National Park at ca. 400xa0m elevation.ResultsThe two species are named B. moneta C.-I Peng, Rimi & C. W. Lin and B. peridoticola Rimi, C.-I Peng & C. W. Lin. Begonia moneta (sect. Baryandra) is similar to B. gueritziana Gibbs, a widespread species of the same section in Borneo, differing in the peltate (vs. basifixed) leaves and the smaller flower parts. Also, their chromosome numbers are different (B. moneta, 2nu2009=u200930; B. gueritziana, 2nu2009=u200928). The peltate and succulent foliage of B. moneta is also reminiscent of B. burttii Kiew & S. Julia and B. payung S. Julia & Kiew, both of sect. Reichenheimia, from Sarawak. Begonia moneta is distinct from the two species in having branched (vs. entire) placental lamellae. Additionally, B. moneta differs from B. burttii in having 4 (vs. 5) tepals in pistillate flowers and markedly unequal (vs. equal) fruit wings. Begonia moneta differs from B. payung in the smaller leaves and conspicuously winged (vs. wingless) capsules. Begonia peridoticola (sect. Petermannia) resembles B. punchak Kiew & S. Julia from limestone areas in Kuching Division, Sarawak, differing in the entire leaf margin (vs. distantly dentate), much larger capsular wings (8–11xa0mm vs. 2–3xa0mm wide) and yellow, spiral (vs. crimson, U-shaped) styles.ConclusionA careful study of the herbarium materials and literature supports the recognition of the two new species. Detailed descriptions, line drawings, color plates, chromsome data, foliar SEM observations and comparisons with phenetically similar species are provided to aid in identification.

Chloroplast and nuclear DNA exchanges among Begonia sect. Baryandra species (Begoniaceae) from Palawan Island, Philippines, and descriptions of five new species

The Philippine island of Palawan is highly biodiverse. During fieldwork there in 2011 & 2014 we found five unknown species in the large genus Begonia. The species are similar in their rhizomatous stems, four-tepaled flowers, inferior two- or three-locular ovaries with bilamellate placentas, and are assignable to Begonia sect. Baryandra. Our observations support the recognition of these as five new species endemic to Palawan: B. elnidoensis, B. gironellae, B. quinquealata, B. tabonensis and B. tenuibracteata which are described here. The five new species were added to phylogenies based Bayesian analysis of nrDNA (ITS) and chloroplast DNA (ndhA, ndhF-rpl32, rpl32-trnL, trnC-trnD), along with 45 other allied ingroup species. A majority of the species show incongruent positions in the two phylogenies, with evidence of prevalent chloroplast capture. Models show chloroplast capture is more likely in plant populations with high levels of inbreeding following a reduction in selfing rate after hybridisation; we suggest that this is a possible explanation for the massive amount of chloroplast exchange seen in our phylogeny, as Begonia species often exist as small isolated populations and may be prone to inbreeding depression. Our data also indicate a level of nuclear genetic exchange between species. The high prevalence of hybrid events in Begonia is potentially an important factor in driving genomic change and species evolution in this mega-diverse genus.

Three new species of Begonia (Begoniaceae) from Limestone Hills in southwestern Sarawak, Borneo

Most species of Begonia in Borneo, like those of other areas, are narrowly distributed and site-specific. In this study we report three new species of Begonia, namely B. felis C. W. Lin & C.-I Peng, B. kuchingensis C. W. Lin & C.-I Peng (sect. Petermannia) and B. serianensis C. W. Lin & C.-I Peng (sect. Reichenheimia) from the Padawan-Serian limestone hills in southwestern Sarawak. In addition to the taxonomic account, color plates, line drawings, a distribution map, and comparisons with phenetically similar species are provided to aid in identification.

Three new species of Begonia sect. Baryandra from Panay Island, Philippines

BackgroundThe flora of Panay Island is under-collected compared with the other islands of the Philippines.xa0In a joint expedition to the island, botanists from Taiwan and the Philippines found three unknown Begonia species and compared them with potentially allied species.ResultsThe three species are clearly assignable to Begonia sect. Baryandra which is largely endemic to the Philippines. Studies of literature, herbarium specimens, and living plants support the recognition of the three new species:xa0Begonia culasiensis, B. merrilliana, and B. sykakiengii. Somatic chromosomes at metaphase were determined to be 2nxa0=xa030 for B. culasiensis and 2nxa0=xa028 for both B. merrilliana and B. sykakiengii, congruent with those of most species in sect. Baryandra. Molecular phylogenetic evidence is consistent with B. culasiensis being a relict from the late Miocene and B. merrilliana and B. sykakiengii being younger species of Pleistocene origin.ConclusionThe continuing discovery of endemic Philippine species means the remaining fragments of both primary and secondary native vegetation in the archipelago are of increasing value in terms of natural capital. A secure future for the species could be realized through ex situ conservation collections and raising awareness with community groups.