Search for: All records

Abstract Understanding biodiversity is critical for the proper conservation of ecosystems experiencing extreme stress from global change. Few other ecosystems are at such high risk of disappearing, especially due to logging and agricultural activities, as the Massif de la Hotte, a chain of mountains in Haiti on the island of Hispaniola, located within the Caribbean Biodiversity Hotspot. We used the hyperdiverse tropical plant family Melastomataceae to understand the biogeographical history and endemism patterns in a major hotspot for the family, the Massif de la Hotte, Haiti. Our goal was to determine the number, timing, and geographical origin of introductions of Melastomataceae (particularly Miconieae) into the Massif de la Hotte. We also aimed to identify whether the Massif de la Hotte and neighbouring ranges on Hispaniola and Cuba were so-called museums or cradles of biodiversity, and determine the extent that areas of high diversity and endemism overlap with currently conserved lands. In total, our analyses uncovered 19 independent dispersal events of Miconieae to the Massif de la Hotte. The Mecranium, Brevycima, and Meriania clades all had rapid radiations consisting of narrow endemics inferred to be of Massif de la Hotte origin. Species of the Chaenopleura clade in the Massif de la Hotte were mostly products of solitary dispersal events from eastern Cuba or the Massif de la Selle. The Massif de la Hotte endemics in the Caribbean Clade were largely the result of dispersal events from central and eastern Cuba. Eastern Cuba is also inferred as the ancestral area for many Massif de la Hotte endemic clades. A total of 25 10 × 10-km grid cells were found by CANAPE to contain significant endemism, with a high proportion of endemism hotspots over the Massif de la Hotte and eastern Cuba. Overlap of these significant CANAPE cells with currently protected areas was high (∼90%). Elucidating phylogenetic diversity and endemism patterns across the vastly different ecosystems of this biodiversity hotspot will aid in our understanding of how these biodiverse forests were formed. 

ABSTRACT Anisophylly is a peculiar leaf trait in some opposite‐leaved taxa where opposing leaves are distinctly unequal. This study uses an expert‐curated specimen dataset to explore relationships of canopy cover and climate with the presence and intraspecific variation of anisophylly in the genusTriolena.Canopy and climate conditions are investigated between species and within a single species through beta regression models. No relationship was found between canopy cover and anisophylly. However, anisophylly is associated with conditions of high precipitation and high isothermality, which is evident acrossTriolenaand within a single species. In addition, partitioned ecoregion analyses illustrate that different types of anisophyllous leaf states occur in distinct ranges of precipitation and isothermality. Results suggest that anisophylly is associated with climate inTriolena. 

Abstract PremiseA probe set was previously designed to target 384 nuclear loci in the Melastomataceae family; however, when trying to use it, we encountered several practical and conceptual problems, such as the presence of sequences in reverse complement, intronic regions with stop codons, and other issues. This raised concerns regarding the use of this probe set for sequence recovery in Melastomataceae. MethodsIn order to correct these issues, we cleaned the Melastomataceae probe set, extended it with additional sequences, and compared its performance with the original version. ResultsThe final probe set targets 396 putative nuclear loci represented by 6009 template sequences. The probe set has been made available, along with details on the cleaning process, for reproducibility. We show that the new probe set performs better than the original version in terms of sequence recovery. DiscussionThis updated, extended, and cleaned probe set will improve the availability of phylogenomic resources across the Melastomataceae family. It is fully compatible with sequence recovery and extraction pipelines. The cleaning process can also be applied to any plant‐targeting probe set that would need to be cleaned or updated if new genomic resources for the targeted taxa become available. 

Summary A new species ofTriolena,endemic to Colón Province, Panama, is described and illustrated. The specimens of this taxon were previously identified asTriolena lanceolata, but closer inspection has shown them to be morphologically and geographically distinct.Triolena anisophyllaK.Samra & Michelang. grows on rocks and tree trunks along rivers in Colón Province. This species is distinguishable by its strongly anisophyllous leaves and unique trichomes on the adaxial surface of the leaves. A complete description, distribution map, preliminary conservation assessment, taxonomic notes, and regional key are provided. 

Abstract 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. 

Blakea viridis (Melastomataceae: Pyxidantheae), a new species from southern Peru is described. Blakea viridis is characterized by having floral pedicels 5.7–6 cm long, greenish petals 10 mm long, and greenish bracts, which provided the reason for the epithet. This new species is known from only three collections from within the Cusco region of Peru. 

Pseudoernestia (Melastomataceae: Marcetieae) is a genus comprising two species, P. cordifolia and P. glandulosa, with disjunct distributions along the Amazon Rainforest. The genus is characterized by narrow sepals, petals bearing an apical glandular trichome, antesepalous stamens with aristate ventral appendages and calcarate dorsal appendages positioned opposite the ventral ones, a glabrous ovary with three locules, rarely two, and seeds lacking dorsolateral projections. We present a taxonomic review of Pseudoernestia, including a lectotypification for P. cordifolia, the type species of the genus. Based on herbarium data, we confirmed that P. cordifolia occurs in Venezuela and Brazil, typically on rocky outcrops, whereas P. glandulosa is found in French Guiana and Guyana, primarily on lateritic soils. Pseudoernestia cordifolia is categorized as Endangered, while P. glandulosa is assessed as Least Concern. We provide detailed descriptions, photographs of living specimens, scanning electron microscopy images of the seeds, geographic distribution maps, and notes on conservation status, habitat preferences, and phenology.