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The Greater Antilles are renowned as a biodiversity hotspot and known to be geologically complex, which has led, in part, to the generation of organismal diversity in this area. One of the most species-rich montane groups within the Greater Antilles is the tribe Miconieae (Miconia s.l.) of the Melastomataceae, with ca. 325 species found there. The most diverse clade of Miconia in the Caribbean, the Caribbean clade, composes roughly half of that diversity, with an estimated 160 species, nearly all of which are endemic to the Greater Antilles. It is unclear how that diversity has been generated through time or where it originated, but we now have sufficiently well-sampled and robust datasets to test these patterns. Using a custom-built plastome dataset, we generated a robust phylogenetic hypothesis for 106 of the 160 Caribbean clade members and tested biogeographical patterns among the islands. Our results suggest that the Caribbean clade originated in the mid-Miocene, probably from a South American ancestor, and diversified substantially on the island of Cuba before repeatedly dispersing across other parts of the Greater Antilles, especially into nearby Hispaniola and then, to a lesser extent, into Jamaica, Puerto Rico and, finally, into the Lesser Antilles. [ABSTRACT FROM AUTHOR]

A narrowly endemic new species of Gesneria is described from the Sierra de Bahoruco in the Dominican Republic's Barahona Peninsula of southern Hispaniola. Gesneria tuberifera J.L.Clark & T.Clase, sp. nov. differs from all other congeners by the presence of a tuber and tubular red corollas with yellow lobes. Images and a discussion are provided to summarize the presence of tubers in other Gesneriaceae and differentiate Gesneria tuberifera from congeners that share a lithophytic habit. Based on IUCN guidelines, a preliminary conservation status of Endangered (EN) is assessed for G. tuberifera. [ABSTRACT FROM AUTHOR]

The Antillean genus Leptocereus represents an in-situ radiation among the Greater and Lesser Antilles of 19 currently recognized species. Extensive fieldwork carried out in the Dominican Republic over recent years has revealed that the species limits of Leptocereus of Hispaniola are more complex than previously thought. There are four currently recognized species that occur on the island, L. demissus, L. paniculatus, L. undulosus and L. weingartianus. We evaluate species limits in this group based on DNA sequence data and phylogenetic analysis, morphological characters and a survey of herbarium specimens from across Hispaniola. Based on our analyses, it is clear that at least five species occur on the island of Hispaniola, with the new species from Sierra de Bahoruco, L. velozianus, described here. We provide an identification key, distribution maps and photographic plates for all species on Hispaniola based on our own fieldwork and the study of herbarium specimens. The description of yet another species of Leptocereus on Hispaniola reiterates the importance of the poorly studied, but yet biodiverse, seasonally dry tropical forest in the Antilles. [ABSTRACT FROM AUTHOR]

Premise of research. To safeguard threatened plant species, best-practice guidelines and genetic modeling emphasize that ex situ collections should be composed of high numbers of maternal lines. Threatened species often present challenges to meeting this standard due to biology or logistics. An approach that pools garden collections into a single larger metacollection may be more effective at capturing genetic diversity. This study examines the genetic capture of a metacollection and compares this with an idealized model for ex situ sampling. Methodology. The model species, Pseudophoenix ekmanii (cacheo palm), was chosen for its threat status, presence in collections, and reproductive limitations. In total, 171 in situ plants were compared with 91 ex situ plants via 10 microsatellite markers. Three cohorts representing both legacy (older) collections and a deliberately structured (recent) conservation collection were pooled and compared. Bootstrapped resampling of these ex situ cohorts was compared with resamples of in situ genotypes to evaluate the collection compared with idealized models of allele capture. Pivotal results. Genetic distance analysis and fixation indexes show weak geographic structure of ex situ collections compared with in situ subpopulations and their close identity to the source population. Pooling together ex situ collections increased allele capture and increased efficiency of allele capture. Modeled allele capture from in situ genotypes exceeded allele capture currently found in ex situ collections. Conclusions. These data demonstrate that botanic gardens may better conserve genetic diversity of in situ plants by following three recommendations: (1) pool ex situ resources into metacollections, (2) share data to better inform new collections, and (3) emphasize logistic and biological parameters of the target species over idealized models for ex situ conservation. [ABSTRACT FROM AUTHOR]

Pseudophoenix ekmanii, P. lediniana and P. vinifera ( Arecaceae) are endemic to Hispaniola. The more wide-ranging P. sargentii also occurs on the island. Population genetic diversity and structure of Pseudophoenix was investigated using ten microsatellite loci. The study focused on populations from Hispaniola, but also included samples from other Caribbean islands. Results showed homozygote excess and high inbreeding coefficients in all populations across all polymorphic loci. Populations were highly differentiated. Results from both Bayesian and neighbour-joining cluster analyses identified groups that were consistent with currently accepted species delimitations. We included the only known population of a possible undescribed taxon from the Dominican Republic. Results from the cluster analyses suggested that this putative taxon is closely related to P. sargentii from the Turks and Caicos Islands. There was no significant correlation between population size and observed heterozygosity. Contrary to what was anticipated, protected areas do not harbour most of the genetic diversity of the genus. The Haitian endemic P. lediniana should have the highest priority for conservation because it is restricted to a single population, it has a small number of individuals and it exhibited reduced levels of genetic diversity. The putative new taxon from the Dominican Republic has similar conservation concerns. Future conservation efforts should aim to maintain population connectivity and increase population size, particularly targeting populations with low genetic diversity. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176, 469-485. [ABSTRACT FROM AUTHOR]

The article presents information on the conservation of native flora of Caribbean Island and opening of seed bank of the Jardín Botánico Nacional at Santo Domingo in the Dominican Republic.

A narrowly endemic new species of Gesneria is described from the Sierra de Bahoruco in the Dominican Republic's Barahona Peninsula of southern Hispaniola. Gesneriatuberifera J.L.Clark & T.Clase, sp. nov. differs from all other congeners by the presence of a tuber and tubular red corollas with yellow lobes. Images and a discussion are provided to summarize the presence of tubers in other Gesneriaceae and differentiate Gesneriatuberifera from congeners that share a lithophytic habit. Based on IUCN guidelines, a preliminary conservation status of Endangered (EN) is assessed for G.tuberifera ., Competing Interests: The authors have declared that no competing interests exist., (John L. Clark, Teodoro Clase.)