Molecular evidence for phylogenetic relationships of Jacquemontia reclinata House (Convolvulaceae) – a critically endangered species from south Florida

Jacquemontia reclinata House (Convolvulaceae) is a federally listed endangered species endemic to coastal strand habitat of south-eastern Florida. In order to identify the closest relatives of J. reclinata , a phylogenetic reconstruction was performed based on nucleotide sequence data from the internal transcribed spacer region of nuclear ribosomal DNA and from the trnH-psbA intergenic spacer of chloroplast DNA. The three putative relatives of J. reclinata and the majority of Jacquemontia Choicy species known to occur in the Caribbean Islands were included. The strict consensus tree concurs with previous morphological studies, indicating that J. reclinata is closely related to the Caribbean species J. cayensis Britton, J. curtisii Hallier f., and J. havanensis (Jacq.) Urb. These three species and J. reclinata form an unresolved clade. Nucleotide divergence within this clade is low, suggesting that the group is recent, perhaps diversifying after the latest glacial period. These taxa need to be studied further using population-level DNA markers. Most species endemic to the Caribbean Basin form a strongly supported clade. Our phylogeny supports Convolvulus nodiflorus Desr. as part of Jacquemontia . In addition, J. ovalifolia (West) Hallier f. ssp. sandwicensis (A. Gray) K.R. Robertson is sister to the Antillean endemic J. solanifolia (L.) Hallier f. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 443–454.     

Successive cambia in Aizoaceae: products and process

The transverse and longitudinal sections of the stems and roots of 11 genera of Aizoaceae, representing a wide range of growth forms from hard fibrous stems to fibre‐free roots, were studied using light microscopy and scanning electron microscopy. In most of the genera, fibres are the first xylary product of each vascular cambium, followed by vessels in a parenchyma background. Variations on this pattern help to prove that fibres are produced by vascular cambia, except in Ruschia and Stayneria, in which both the lateral meristem and the vascular cambia produce fibres. Cylinders of conjunctive tissue parenchyma that alternate with the vascular cylinders are produced by the lateral meristem. The concept that the lateral meristem gives rise to the vascular cambia and secondary cortex is supported by photographic evidence. Radial divisions occur in the origin of the lateral meristem, and then again as vascular cambia arise from the lateral meristem; these radial divisions account for storeying in fibres and conjunctive tissue. Raylessness characterizes all Aizoaceae studied, with the exception of Tetragonia, which also differs from the remaining genera by having vasicentric axial parenchyma, a scattering of vessels amongst fibres, and the presence of druses instead of raphides. Several vascular cambia are typically formed per year. Several vascular cambia are active simultaneously in a given stem or root. Roots have fewer fibres and more abundant conjunctive tissue parenchyma than stems. Successive cambia result in an ideal dispersion of vascular tissue with respect to water and photosynthate storage and retrieval capabilities of the parenchyma, and to liana stem plans. The distribution and relative abundance of fibres, vessels, secondary phloem, and conjunctive tissue parenchyma relate primarily to habit and are not a good source of systematic data, with the probable exception of Tetragonia. The general pattern of lateral meristem and vascular cambial ontogeny is the same as in other families of the core Caryophyllales, although the patterns of the tissues produced are diverse. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 153 , 141–155.     

An evaluation of the taxonomic distinctness of two Geonoma macrostachys (Arecaceae) varieties based on intersimple sequence repeat (ISSR) variation

The latest taxonomic account for the palms of the Amazon recognizes two common and widespread varieties of Geonoma macrostachys (Arecaceae) in western Amazonia: acaulis and macrostachys . These varieties are joined by intermediates, which obscure their taxonomic boundaries. An evaluation of the genetic distinctness between G. macrostachys varieties at a local and regional scale is presented. Thirty-one G. macrostachys individuals were randomly sampled from four Peruvian tropical moist forests. Twenty-seven intersimple sequence repeat (ISSR) primers were used, and all clear and reproducible bands were scored and analysed. Of the 99 ISSR bands produced, 51.52% were polymorphic. Nei's gene diversity value ( H ) was 0.2274 and Shannon's information index ( I ) was 0.3237. Clustering, ordination, and analyses of molecular variance (AMOVAs) suggested a lack of genetic distinctness between varieties at the regional level. Individuals clustered by geographical provenance, and two main groups were identified. A significant genetic differentiation between sympatric varieties occurred only in the northern locality (Φ_ST = 0.359, P  = 0.000). A hierarchical AMOVA revealed that the genetic diversity in G. macrostachys mainly lies between localities (76.58%). Mantel's test revealed no significant correlation between the geographical and genetic distances between individuals. We do not support the recognition of the two taxonomic varieties studied.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 381–392.     

What's in a name? Or a namer's name? A reply to Dubois (2008)

Dubois recently suggested that Linnean taxa should be quoted with the year of publication only, rather than with the author ± year of publication. This would reduce the perceived artificial nomenclatural inflation produced by new synonyms. We do not consider this inflation a problem and recommend the maintenance of the current methodology. This has several advantages over that suggested by Dubois, including easy identification of taxa introduced by splitters, which are known by name, not year of publication; managers of systematic facilities expect to see their institute's papers cited; most systematists are dead, but recognition of their efforts is fitting; and a complete reference of author and year supports the best scholarship. Present and future systematists would be better served if Dubois' recommendation was not implemented. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96 , 709–711.     

Distinctive tracheid microstructure in stems of Victoria and Euryale (Nymphaeaceae)

Scanning electron microscopy (SEM) photographs of thick sections from liquid‐preserved stems of Victoria cruziana and Euryale ferox show accretions of coarse fibrils on pit membranes of tracheids. The first‐deposited fibrils are randomly orientated; on top of them (facing the tracheid lumina) are axially orientated coarse fibrils. The two systems are interconnected. Axially orientated fibrils were more extensively observed in Euryale than in Victoria and tips of fibrils in Euryale extend over the pit apertures onto secondary wall surfaces. Tracheid–parenchyma interfaces bear rudimentary coarse fibrils on the tracheid side. End walls of Victoria tracheids have highly porose pit membranes, thinner and less complex than those of the lateral intertracheid walls. The structures reported in Victoria and Euryale are consistent with those concurrently reported for stems of other Nymphaeaceae. Although also present in Cabombaceae, the coarse fibrils are otherwise not reported for stems of angiosperms and are not yet reported in roots of any species. Pit membrane remnants in perforation plates of various woody dicotyledons represent a nonhomologous phenomenon. The accretions of coarse fibrils in stem tracheids of Nymphaeaceae do not appear to enhance conduction, although they do contain porosities interconnecting tracheids. Removal of pit membrane remnants from perforation plates of primitive dicotyledon woods by hydrolysis does, on the contrary, suggest conduction enhancement. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 52–57.     

Bivalvia – a look at the Branches

Systematic research on bivalved molluscs (Mollusca: Bivalvia = Pelecypoda) is briefly reviewed in an introduction to a series of papers focusing on seven of the larger branches of the bivalve tree. These are presented in an attempt to summarize current knowledge, to stimulate new research and to highlight needs for future research focus. A revised classification of extant bivalve families (with synonyms and included subfamilies) is presented, based on information compiled from the latest palaeontological, morphological and molecular data.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 223–235.     

The systematics and biology of the Costa Rican species of parasitic wasps in the Thyreodon genus-group (Hymenoptera: Ichneumonidae)

This paper presents an eco‐taxonomic study of the Neotropical representatives of the Thyreodon genus‐group (Hymenoptera: Ichneumonidae) present in Costa Rica, i.e. species of the genera Thyreodon and Rhynchophion. These ichneumonids are koinobiont endoparasitoids of the larvae of Sphingidae and Saturniidae. Intensive sampling in Costa Rica, conducted over 15 years, has revealed the presence of 23 species (12 of which are described here as new –Rhynchophion woodi, Thyreodon woodleyi, T. papei, T. whitfieldi, T. deansi, T. walkerae, T. sharkeyi, T. zitaniae, T. delvarei, T. schauffi, T. darlingi and T. carmeani), whereas earlier studies recognized only nine species in the same area. Several of the additional species we found are simply very scarce and thus unlikely to be encountered except by the type of intensive survey that, in the tropics, has only been conducted in Costa Rica. In some other cases, it has become apparent that more than one species has previously been confused under a single name. Thyreodon rufothorax Cameron is shown to be morphologically and biologically distinct from T. atriventris (Cresson), with which it has long been synonymized, and the relatively well‐known, chromatically distinctive species ‘T. laticinctus Cresson’ and ‘T. morosus Smith’ are both shown to be complexes of sibling species. Reared series have been essential in facilitating the separation of the species in these complexes. An illustrated key is provided to separate all taxa using simple morphological characters. Fourteen of the 23 species have been reared, and all have been found to be restricted to one or a few species of hosts, species of Thyreodon primarily on macroglossine Sphingidae (with one species on Saturniidae) and species of Rhynchophion on sphingine sphingids of the genus Manduca. No two species of these ichneumonids attack the same host caterpillar species, and not all species of macroglossines present in the study area are attacked by species in this genus‐group. Most species are apparently rather rare. Many have only been collected by rearing on a few occasions, other species have been collected at light (six in total) or in Malaise traps (ten in total), or by hand‐netting (20 in total), but no one method collected all of the species present in the principal study area, the Area Conservacion de Guanacaste. The two New World genera Rhynchophion and Thyreodon are found to be related to the Old World genera Dictyonotus and Euryophion, the former of which comprises species that are also sphingid parasitoids, whereas species of the latter attack the caterpillars of other large bombycoid moths, Saturniidae and Eupterotidae. A cladistic analysis shows that Thyreodon is the sister‐lineage to Dictyonotus, and Euryophion is the most basal lineage in the genus‐group. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141 , 297–351.     

The family Alestidae (Ostariophysi, Characiformes): a phylogenetic analysis of a trans-Atlantic clade

The overall most parsimonious hypothesis of relationships based on 200 characters indicates that the Alestidae is the closest relative of Chalceus , a genus previously assigned to the Neotropical Characidae. Chalceus is shifted into the Alestidae, which becomes the only trans-Atlantic family level group within the Characiformes. Various previously proposed suprageneric assemblages within the Alestidae (e.g. Petersiini) failed to delimit monophyletic groups under the intrafamilial phylogenetic analysis. The evaluation of fossil alestids within the context of the phylogeny indicates that the ancestors of Alestes , Arnoldichthys , Brycinus , Bryconaethiops and Hydrocynus evolved prior to the early Eocene (Cuisian of Upper Ypresian), 49–54.8 million years ago, with the fossil Alestoides most closely related to Alestes. The phylogenetic information further indicates a minimum age of 90–112 million years for the Alestidae. Contrary to previous hypotheses, the fossil African Sindacharax was found to be most similar to the clade including the alestid genus Bryconaethiops rather than most closely related to the South American subfamily Serrasalminae. Evaluation of the fossil Mahengecharax carrolli fails to support its hypothesized placement as the sister group to all Recent members of the Alestidae. Two separate episodes of miniaturization and one episode of gigantism occurred within the evolution of the Alestidae.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 145 , 1−144. No claim to original US government works.