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We undertook a phylogenetic analysis of sequences of the internal transcribed spacers (ITS) of the nuclear ribosomal DNA to test the hypothesis that the Canary Island genus Vierea is closely related to Pulicaria sect. Vieraeopsis, a taxon with four species restricted to Socotra and Southern Arabia. The ITS tree does not support this relationship, although many of the nodes were weakly supported (bootstrap value below 75%). Vierea is sister to the Mediterranean genus Perralderia (bootstrap support 74%). We suggest that morphological similarities between Vierea and Pulicaria sect. Vieraeopsis are due mostly to morphological convergence. It is thus concluded that these two taxa do not share a common history. A review of molecular phylogenetic studies of taxa considered to represent putative biogeographical links between Macaronesia and Southern Arabia and/or distant regions of Africa, is also presented. With a few exceptions most of these putative relationships are not supported by molecular phylogenies. Additional cladistic studies are needed for at least 15 genera or sections with a predominant disjunct phytogeographical distribution between Macaronesia, East/South Africa and Southern Arabia.

A molecular phylogenetic study of Bystropogon L'Her. (Lamiaceae) is presented. We performed a cladistic analysis of nucleotide sequences of the internal transcribed spacers (ITS), of the nuclear ribosomal DNA, and of the trnL gene and trnL-trnF intergenic spacer of the chloroplast DNA. Bystropogon odoratissimus is the only species endemic to the Canary Islands that occurs in the three palaeo-islands of Tenerife. This species is not part of an early diverging lineage of Bystropogon and we suggest that it has a recent origin. This phylogenetic pattern is followed by most of the species endemic to the palaeo-islands of Tenerife. The two sections currently recognized in Bystropogon form two monophyletic groups. Taxa belonging to the section Bystropogon clade show interisland colonization limited to the Canary Islands with ecological shifts among three ecological zones. Taxa from the section Canariense clade show interisland colonization both within the Canary Islands and between the Canary Islands and Madeira. Speciation events within this clade are mostly limited to the laurel forest. The genus has followed a colonization route from the Canaries towards Madeira. This route has also been followed by at least five other plant genera with species endemic to Macaronesia. Major incongruences were found between the current infrasectional classification and the molecular phylogeny, because the varieties of Bystropogon origanifolius and Bystropogon canariensis do not form two monophyletic groups. The widespread B. origanifolius appears as progenitor of the other species in section Bystropogon with a more restricted distribution.

ABSTRACT. Bystropogon (Lamiaceae) is endemic to the Macaronesian Islands and represents the best-known example of a putative phytogeographic connection between these islands and the New World. Previous morphological taxonomic studies suggested that this genus is closely related to the western South American Minthostachys. Phylogenetic analyses of nucleotide sequences of the internal transcribed spacers and 5.8S subunit of nuclear ribosomal DNA and the trnL gene and trnL-trnF spacer of the chloroplast genome for 33 of the 72 genera in the Mentheae tribe were performed. Maximum parsimony analysis of the combined data set resulted in 63 most parsimonious trees. The strict consensus tree of this analysis shows with moderate bootstrap support (74%) that Bystropogon is sister to the Old World taxa Acinos, Ziziphora, and Clinopodium vulgare. When analyzed separately, the ITS and trnL/F data sets do not agree as to the sister group to Bystropogon, although none supports a sister relationship with Minthostachys. The cpDNA phylogeny strongly supports a relationship of Bystropogon with a clade of New World mint taxa (90% bootstrap value). Due to the apparent conflict between the chloroplast and nuclear characters observed in the phylogenies, we are not certain of the true biogeographic relationship of Bystropogon. Finally, in all analyses, all of the Mentheae genera sampled in this study form a monophyletic group (100% bootstrap value) and a derived clade of ten New World genera is found. These results contribute to our understanding of generic relationships within the tribe.

Cytoplasmic inheritance was investigated in interspecific hybrids of Wisteria sinensis and W. floribunda. Species-specific nuclear, mitochondrial and plastid DNA markers were identified from wild-collected plants of each species in its native range. These markers provide evidence for the bi-parental transmission of plastids in hybrid swarms of these two species in the southeastern USA. These population level molecular data corroborate previous cytological evidence of this phenomenon in Wisteria.

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We investigated whether the plants of the Galápagos Archipelago and Cocos Island, which are each other's closest neighboring insular systems, show any such sister relationships. Five genera of vascular plants have endemics in both archipelagos, including plants with different life histories and dispersal mechanisms: tree ferns, epiphytes, trees, herbs, and shrubs, with adaptations for dispersal by wind or birds (two genera each) or with no obvious dispersal adaptation (one genus). We obtained molecular phylogenies for these genera to test the hypothesis of phytogeographical links between the islands. The phylogenies for all five genera were not consistent with this hypothesis, but they supported floristic studies in revealing no direct phytogeographical links between the islands. We attribute this lack of floristic affinity primarily to air and ocean circulation patterns that limit dispersal between Galá pagos and Cocos and to a low frequency of interisland bird movements. There are also major ecological differences between them, and Cocos Island is quite small, which limits the chance of random dispersal events and subsequent establishment.

This study describes the use of periodic matrix analysis and regression-design life table response experiments (LTRE) to investigate the effects of prescribed fire on demographic responses of Pinguicula ionantha, a federally listed plant endemic to the herb bog/savanna community in north Florida. Multi-state mark-recapture models with dead recoveries were used to estimate survival and transition probabilities for over 2,300 individuals in 12 populations of P. ionantha. These estimates were applied to parameterize matrix models used in further analyses. P. ionantha demographics were found to be strongly dependent on prescribed fire events. Periodic matrix models were used to evaluate season of burn (either growing or dormant season) for fire return intervals ranging from 1 to 20 years. Annual growing and biannual dormant season fires maximized population growth rates for this species. A regression design LTRE was used to evaluate the effect of number of days since last fire on population growth. Maximum population growth rates calculated using standard asymptotic analysis were realized shortly following a burn event (<2 years), and a regression design LTRE showed that short-term fire-mediated changes in vital rates translated into observed increases in population growth. The LTRE identified fecundity and individual growth as contributing most to increases in post-fire population growth. Our analyses found that the current four-year prescribed fire return intervals used at the study sites can be significantly shortened to increase the population growth rates of this rare species. Understanding the role of fire frequency and season in creating and maintaining appropriate habitat for this species may aid in the conservation of this and other rare herb bog/savanna inhabitants.