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Six new species of Begonia sect. Jackia from Sumatra are described and illustrated: B. araneumoides, B. batuphila, B. hijauvenia, B. mursalaensis, B. panjangfolia, and B. perunggufolia. All morphological characters and measurements were observed from living plants in the Bogor Botanical Gardens greenhouse or the wild. Using IUCN criteria, 4 species are considered to be Data Deficient, 1 Vulnerable, and 1 Least Concern. [ABSTRACT FROM AUTHOR]

Begonia phouchomvoyensis, a new species from Phou Chom Voy Provincial Protected Area, Bolikhamxai province, Lao PDR, is described and illustrated. It is placed in Begonia sect. Platycentrum, and is assessed as belonging to the Vulnerable IUCN Category. [ABSTRACT FROM AUTHOR]

Background: The flora of Panay Island is under-collected compared with the other islands of the Philippines. In a joint expedition to the island, botanists from Taiwan and the Philippines found three unknown Begonia species and compared them with potentially allied species. Results: The 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: Begonia culasiensis, B. merrilliana, and B. sykakiengii. Somatic chromosomes at metaphase were determined to be 2 n = 30 for B. culasiensis and 2 n = 28 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. Conclusion: The 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. [ABSTRACT FROM AUTHOR]

Background: Begonia is a mega-diverse genus of flowering plants prone to generating micro-endemic species, especially on limestone habitats. During fieldwork in the Puerto Princesa Subterranean River National Park, Palawan (Philippines), three species were encountered which did not match any previously described from the region. Results: Following morphological, anatomical, molecular phylogenetic and cytological investigation a hypothesis of three new species is supported. The three new species belong to a clade endemic to Palawan and Borneo. Conclusions: The limestone habitats in the Puerto Princesa Subterranean River National Park environs support a unique flora. The description of three new species from a small area within the park demonstrates how much remains to be discovered there, and the importance of its continued protection. [ABSTRACT FROM AUTHOR]

Aim The origin of Neotropical hyperdiversity is one of the most intriguing questions in modern biogeography and is best answered through the investigation of large, pantropically distributed genera, allowing the comparison of closely related clades in different regions. We produced a dated phylogeny and reconstructed ancestral ranges of the megadiverse, Andean-centred genus Begonia to discern its dispersal history throughout the Neotropics and correlates of range evolution. Neotropical and Palaeotropical diversification rates were estimated. Location Neotropics: Central America, South America, West Indies and Mexico. Methods Plastid DNA sequence data from species representing the full geographical range and majority of sections of Neotropical Begonia were analysed with a secondarily calibrated relaxed molecular clock in order to estimate the age of crown groups and divergence times within Neotropical Begonia. Ancestral areas were reconstructed with a Bayesian approach to dispersal-vicariance analysis, a likelihood framework under a dispersal-extinction-cladogenesis model, and a Bayesian binary method. Diversification rates were estimated under a Bayesian framework. Results Biogeographical reconstruction indicated two independent trans-Atlantic colonizations of the Neotropics from Africa. Early-diverging lineages of both clades are reconstructed as having diversified in the mid-Miocene, with multiple dispersal events between the Brazilian Atlantic rain forest and the Andes, and single radiations within the West Indies and Central America plus Mexico. Main conclusions Begonia displays numerous radiations within regions, punctuated by long-distance dispersal. Successful colonization and diversification is predicted by the presence of upland habitat. Recognizing the role of chance dispersal events between available habitats is vital for understanding the formation of current biogeographical patterns. [ABSTRACT FROM AUTHOR]

* Premise of the study: One third of the species-rich Philippine flora is endemic, and most of the islands in the archipelago have never been connected to a continental region. We currently lack any well-sampled angiosperm phylogenies that span the archipelago, prohibiting the formation of informed hypotheses as to the evolution of this rich and highly endemic flora. * Methods: We produced time-calibrated phylogenetic trees from both nuclear (ITS) and chloroplast (ndhA intron, ndhF-rpl32 spacer, rpl32-trnL spacer, trnC-trnD spacer) regions of 41 species of Begonia sect. Baryandra, all except one endemic to the Philippines. Historical biogeography was reconstructed across the chloroplast phylogeny using a Bayesian binary method of character optimization. Comparison of phylogenies from the two genomes permitted insight into the prevalence of hybridization in the group. * Key results: The Philippine archipelago was colonized by Begonia sect. Baryandra in the late Miocene, via long-distance dispersal from western Malesia and a point of entry likely to be in the northwestern region of the archipelago. Palawan, Luzon, and Panay all bear early-branching lineages from this initial colonization. There have been Plio-Pleistocene dispersals from these islands into Borneo and Mindanao. Hybridization was common between species as evidenced by haplotype sharing and phylogenetic incongruence. * Conclusions: The phylogenies show a high degree of geographic structure, which millions of years of exposure to typhoons have not blurred, showing long-term species and population stability. The recent dispersals to Mindanao are congruent with the geologically recent arrival of the island at its current latitude in the southern Philippines. [ABSTRACT FROM AUTHOR]

The pollen morphology of 28 Begonia species of Nepal has been examined by scanning electron microscopy (SEM). Comparative pollen analysis was made based on size, shape in polar and equatorial views, P/E ratio, aperture, and exine ornamentation. In this study, four types of pollen ornamentation morphology have been identified. Among Nepalese Begonia, B. roxburghii (section Sphenanthera) has the smallest pollen (11.2-12.8 × 6.4-7.0 μm) and B. flagellaris (section Diploclinium) has the largest pollen (24.3-30.6 × 11.4-12.0 μm). Presence of margo in the pollen ornamentation is a distinguishing character that separates Begonia section Platycentrum from all other sections of Nepalese Begonia. [ABSTRACT FROM AUTHOR]

A new species of Begonia in sect. Diploclinium, B. blancii M. Hughes & C.-I Peng, is described from the Bulalakaw Falls area in Palawan. A somatic chromosome number of 2n = 30 was determined. Begonia blancii is allied to B. suborbiculata and other 2-locular species in Begonia sect. Diploclinium, but is very distinct in having triangular-spathulate leaves. It shares clustered stomata with a number of other Begonia species, which are likely to help it reduce water loss through transpiration during the dry season. Its IUCN status is considered to be Least Concern. [ABSTRACT FROM AUTHOR]

Addresses the evolution of Begonia by producing maximum parsimony cladograms for nuclear large subunit and internal transcribed spacer sequence data in combination with 34 informative morphological characters. Data obtained from 64 species of Begonia; Nuclear ribosomal sequence data and morphological characters; Phylogenetic hypotheses that supported three main clades within Begonia.