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Explaining how plants from eastern Asia migrated to other Northern Hemisphere regions is still challenging. The genus Sorbus sensu stricto (including c . 88 species) is considered as a good example to illuminate this scenario, due to the wide distribution in the temperate zone and high diversity in the Himalayas and Hengduan Mountains. Based on four nuclear markers ( LEAFY -2, GBSSI -1, SBEI and WD ) and one chloroplast marker ( rps16 - trnK ), we reconstructed the phylogenetic relationship of Sorbus using 54 taxa (60% of the genus representing all subgenera, sections, or series and geographical areas in the previous classifications), and estimated divergence time and historical biogeography of the genus. Phylogenetic analyses supported that the subgenera Sorbus and Albo - carmesinae , as defined by traditional morphological characters (such as fruit color), are suitable. However, five clades defined by phylogenetic analysis of the genus are not consistent with traditionally defined sections or series. Molecular dating and biogeographic reconstruction showed that the age of the most recent common ancestor was estimated at 41 mya (95% HPD: 49–35 mya) in eastern Asia. Four dispersal events are assumed to explain the wide distribution of Sorbus in the temperate zone and diversification in the edges of Qinghai-Tibet Plateau (QTP). Species dispersed from eastern Asia to the Tianshan Mountains, North America and Europe during the Oligocene and Miocene period. We found that polyploidization occurred multiple times in the subgenus Albo - carmesinae , in the Tianshan Mountains, Himalayas, and H-D Mountains. Finally, we suggest that apomixis, polyploidization, and hybridization may have combined with the multistage uplifting of Himalayas and H-D Mountains (and the subsequent increases in geologic, ecological and climatic heterogeneity) to drive the striking species diversity of Sorbus in this region. [ABSTRACT FROM AUTHOR]

Arisaema has a long and complicated taxonomic history regarding its infrageneric classification. In the latest system, 14 sections were recognized, based on an unpublished, tentative phylogenetic analysis; in addition the type species and nomenclatural priority for each section were confirmed. Here, we present an updated, genus-wide phylogenetic analysis, based on four plastid non-coding regions (3 ′trnL- trnF, rpl20-5 ′rps12, psbB- psbH and rpoC2- rps2) for > 150 accessions. The maximum parsimony and maximum likelihood phylogenetic analyses identified eight major clades and one branch with unique sequence variation, although the relationships were unclear due to a polytomy and weak support. In the phylogenetic trees, most of the sections proposed in the latest system were distinct and corresponded to the major clades, but some sections are not monophyletic. On the basis of the phylogenetic relationship: (1) A. schimperianum is treated as a member of section Arisaema, rather than section Tenuipistillata or section Sinarisaema; and (2) section Fimbriata, which was synonymised into section Attenuata in the latest system but is morphologically distinct from the other species, is redefined as a monotypic section. In conclusion, we recognize 15 sections of Arisaema and species-level classifications are discussed in a phylogenetic context. [ABSTRACT FROM AUTHOR]

The article offers information on a study which assessed the relationships among the five sections of Typhonium sensu lato and its allied genera. A background on the plant genus Typhonium is offered. The phylogenetic relationships of Typhonium were analyzed using the combined DNA sequences of six chloroplast regions. Findings of the study suggest that Typhonium is not a monophyletic group and that Typhonium sensu lato may be subdivided into several monophyletic groups.