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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 In the latest system, 14 sections were recognized, based on an unpublished, tentative phylogenetic analysis; in addition the type species and nomenclatural priority for each section were confirmed.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]

Recent molecular phylogenetic studies reported high diversity of Ruppia species in the Mediterranean. Multiple taxa, including apparent endemics, are known from that region, however, they have thus far not been exposed to phylogenetic analyses aimed at studying their relationships to taxa from other parts of the world. Here we present a comprehensive phylogenetic analyses of the R. maritima complex using data sets composed of DNA sequences of the plastid genome, the multi-copy nuclear ITS region, and the low-copy nuclear phyB gene with a primary focus on the Mediterranean representatives of the complex. As a result, a new lineage, 'Drepanensis', was identified as the seventh entity of the complex. This lineage is endemic to the Mediterranean. The accessions included in the former 'Tetraploid' entity were reclassified into two entities: an Asia-Australia-Europe disjunct 'Tetraploid_α' with a paternal 'Diploid' origin, and a European 'Tetraploid_γ' originating from a maternal 'Drepanensis' lineage. Another entity, 'Tetraploid_β', is likely to have been originated as a result of chloroplast capture through backcrossing hybridization between paternal 'Tetraploid_α' and maternal 'Tetraploid_γ'. Additional discovery of multiple tetraploidizations as well as hybridization and chloroplast capture at the tetraploid level indicated that hybridization has been a significant factor in the diversification of Ruppia. [ABSTRACT FROM AUTHOR]

Two woodyHibiscusspecies co-occur in the Bonin Islands of the northwestern Pacific Ocean:Hibiscus glaberMatsum. is endemic to the islands, and its putative ancestral species,Hibiscus tiliaceusL., is widely distributed in coastal areas of the tropics and subtropics. To infer isolating mechanisms that led to speciation ofH. glaberand the processes that resulted in co-occurrence of the two closely related species on the Bonin Islands, we conducted molecular phylogenetic analyses on chloroplast DNA (cpDNA) sequences. Materials collected from a wide area of the Pacific and Indian Oceans were used, and two closely related species,Hibiscus hamaboSiebold Zucc. andHibiscus macrophyllusRoxb., were also included in the analyses. The constructed tree suggested thatH. glaberhas been derived fromH. tiliaceus,and that most of the modern Bonin populations ofH. tiliaceusdid not share most recent ancestry withH. glaber.Geographic isolation appears to be the most important mechanism in the speciation ofH. glaber.The co-occurrence of the two species can be attributed to multiple migrations of different lineages into the islands. While a wide and overlapping geographical distribution of haplotypes was found inH. tiliaceus, localized geographical distribution of haplotypes was detected inH. glaber. It is hypothesized that a shift to inland habitats may have affected the mode of seed dispersal from ocean currents to gravity and hence resulted in geographical structuring ofH. glaberhaplotypes. [ABSTRACT FROM AUTHOR]

The article validates the new combinations wherein Typhonium s.l. was divided into four genera based on molecular phylogeny and morphology where Typhonium sections Diversifolia Scrinoonma et J. Murata, Pedata Sriboonma et J. Mura and Hirsuta Sriboonma et J. Murata were transferred to a generic rank. These new combinations include Typhonium diversifolium, Typhonium alpinum under Diversiarum and Typhonium hirsutum under Hirsutiarum.