Temporal genetic structuring of a specialist parasitoid,Lysiphlebus hirticornis Mackauer (Hymenoptera: Braconidae) attacking a specialist aphid on tansy

In insect species characterized by inbreeding, limited dispersal, and a metapopulation structure, high genetic differentiation and reduced genetic diversity within local populations are expected. Using the model system Lysiphlebus hirticornis Mackauer, a specialist parasitoid of the tansy aphid, Metopeurum fuscoviride Stroyan (Hemiptera: Aphididae), we examined within‐site temporal population dynamics and genetics, including molecular variation at the tansy plant level. Aphid‐parasitoid dynamics were surveyed and parasitoids sampled from 72 tansy plants at 11 sites in and around Jena, Germany, over one growing season. Thereafter, parasitoid samples were genotyped at 11 polymorphic microsatellite loci. Colonization, extinction, and recolonization events occurred during the season. Allele numbers and identities were highly variable over time. When samples from all sites were pooled, allele number over all loci showed a decreasing trend with time. At the level of sites, temporal changes in genetic diversity were more variable. Analysis of molecular variance revealed that samples at the plant level explained the highest variance compared to at site level. We conclude that the genetic structuring of this insect is very fine grained (i.e. at the tansy plant level) and the temporal genetic diversity is explained by a combination of extinction and recolonization events, as well as inbreeding. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 737–749.     

The stomatal apparatus of Lycopodium japonicum and its bearing on the stomata of the Devonian lycophyte Drepanophycus spinaeformis

The structure of the stomatal apparatus of the leaf of Lycopodium japonicum Thumb was studied using epidermal macerations, sections and scanning electron microscopy. The stomatal apparatus of L. japonicum consists of two large guard cells and pore, and is anomocytic. Based on light microscopy, the impression from epidermal macerations that there were two small guard cells surrounded by two, large, similarly shaped, subsidiary cells (paracytic) derives from a pronounced elliptical cuticular ledge on the surface of the guard cells surrounding a thickened circumporal area. A similar appearance is characteristic of cuticle preparations of the Devonian lycophyte Drepanophycus spinaeformis Göppert. We therefore conclude, as did W.H. Lang over 70 years ago, that the stomata of the early lycophyte were also anomocytic, as were those of a second species of Drepanophycus , D. qujingensis Li & Edwards.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 209–216.     

The importance of looking at small-scale patterns when inferring Gondwanan biogeography: a case study of the centipede Paralamyctes (Chilopoda, Lithobiomorpha, Henicopidae)

Gondwanan biogeography has fascinated zoologists and botanists for over a century, but most biogeographical work has used continent-scale areas as analytical units. More finely resolved patterns, as can be obtained from small invertebrates with limited dispersal abilities, will be obscured in those studies. A common case is treating Australia as a single biogeographical region. In the present study, the necessity of splitting Australia into multiple microareas is demonstrated using centipedes as an example. The lithobiomorph centipede Paralamyctes is distributed on fragments of Gondwana, with species in southern Africa, Madagascar, southern India, Patagonia, eastern Australia, and New Zealand. A cladogram for Paralamyctes is based on morphology and sequences for four molecular markers for 30 terminals that sample 20 of 26 known ingroup species and four outgroups. Analysis with direct optimization across a range of indel costs and transversion : transition cost ratios identifies two main clades: Paralamyctes ( Paralamyctes ) unites species from southern Africa, Madagascar, tropical and warm temperate Australia, and New Zealand. The other group includes the temperate Australian/New Zealand Paralamyctes ( Haasiella ) and Paralamyctes ( Thingathinga ) and a Chilean clade. Subtree analysis finds that different parts of Australia have closest affinities to other Gondwanan fragments, and some of these relationships (such as that between north Queensland and New Zealand) are based on taxonomically stable clades. Area delimitation for large continental fragments should use sufficiently fine resolution to test the 'monophyly' of those fragments and attempt to eliminate spurious geographical paralogy.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 65–78.     

Morphological and allozyme diversity in the Hieracium nigrescens group (Compositae) in the Sudety Mountains and the Western Carpathians

The overall pattern of morphological variation and genetic diversity (allozyme analysis) was studied in the Hieracium nigrescens group (H. nigrescens s.l., H. alpinum ≥ H. murorum) in the Sudety Mountains and the Western Carpathians. A morphological analysis was performed on 180 plants from 12 populations belonging to six a priori distinguished taxa. Altogether, 25 characters were measured or scored. Morphometric (canonical discriminant analysis) data separated five taxa, evaluated here at the species rank: H. chrysostyloides, H. decipiens, H. nigrescens (all from the Sudety Mountains), H. jarzabczynum, and H. vapenicanum (the Western Carpathians). A distinct local population from Mount Babia hora (the Western Carpathians) comprised a further possible taxon, given the preliminary name ‘H. babiagorense’. Genetic diversity was studied in 17 populations of H. chrysostyloides, H. decipiens, H. jarzabczynum, H. nigrescens, H. vapenicanum and ‘H. babiagorense’ using five enzyme systems. All a priori recognized species were proved to be genetically homogeneous, each consisting of one unique multilocus allozyme genotype, except ‘H. babiagorense’ which shared the same genotype with H. jarzabczynum. For the first time, a chromosome number is reported for H. vapenicanum (2n = 3x = 27) and previously published numbers were confirmed for H. chrysostyloides (2n = 5x = 45), H. decipiens (2n = 4x = 36), H. jarzabczynum (2n = 4x = 36), H. koprovanum (2n = 4x = 36), and H. nigrescens (2n = 4x = 36). All species have been shown to be endemic to either the Sudety Mountains or the Western Carpathians. Except for the species studied, two further ones (H. apiculatum, H. nivimontis) are recognized in the area, giving a total of seven species from the Hieracium nigrescens group in the area studied. The morphologically slightly different local population from Mount Babia hora/Babia Góra (‘H. babiagorense’) requires further study. Two new combinations are proposed: Hieracium jarzabczynum (Paw?. & Zahn) Mráz & Chrtek f. and Hieracium vapenicanum (Lengyel & Zahn) Chrtek f. & Mráz. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 153 , 287–300.     

A phylogenetic study of the neotropical catfish family Cetopsidae (Osteichthyes, Ostariophysi, Siluriformes), with a new classification

A hypothesis on the phylogenetic relationships of the neotropical catfish family Cetopsidae is proposed on the basis of the parsimony analysis of 127 morphological characters and most of the species currently recognized. The family and its two recognized subfamilies, the Cetopsinae and Helogeninae, are corroborated as monophyletic, in agreement with recent studies. Previously proposed classifications of the Cetopsinae, however, were found to be poorly representative of the phylogenetic relationships within the subfamily. Major generic rearrangements are implemented in order that the classification of the Cetopsinae reflects the phylogenetic hypothesis. Pseudocetopsis Bleeker (1862) was found to be polyphyletic and to include several disjunct lineages. One of these lineages, recently named as the genus Cetopsidium Vari, Ferraris, and de Pinna (2005), is the sister group to the rest of the Cetopsinae. Denticetopsis Ferraris (1996) is the next sister group to the remainder of the Cetopsinae. The remaining species of the Cetopsinae belong to one of two sister genera, Paracetopsis Bleeker (1862) and Cetopsis Spix and Agassiz (1829). The latter genus includes species formerly assigned to Hemicetopsis Bleeker (1862), Bathycetopsis Lundberg and Rapp Py‐Daniel (1994) and Pseudocetopsis Bleeker (1862). Continued recognition of Hemicetopsis and Bathycetopsis would have required the creation of several additional new genera for various species previously in Pseudocetopsis that form a series of sister groups to a clade composed of Cetopsis oliveirai (Lundberg and Rapp Py‐Daniel, 1994), C. coecutiens (Lichtenstein, 1819) and C. candiru (Spix and Agassiz, 1829). Cetopsis oliveirai is a highly paedomorphic species that displays surprising similarities with conditions in juvenile specimens of C. coecutiens, a species that attains a large body size. Such similarities are not evident in adult specimens of the latter species. A new classification is proposed, within which the subfamily Cetopsinae consists of three tribes, the Cetopsidiini, the Cetopsini and the Denticetopsini. The results of the study form the basis for a discussion of the phylogenetic position of the family within the Siluriformes, the phylogenetic biogeography of the Cetopsidae, paedomorphosis and gigantism in the family, and the effect of different semaphoronts on the intrafamilial phylogeny. Journal compilation © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150 , 755–813. No claim to original US government works.     

The uniqueness of palms

Palms build tall trees entirely by primary growth in a way that limits their growth habit, but not their capacity for continued stem development. They achieve massive primary stature because of distinctive features of leaf development, stem vasculature and anatomical properties. They exhibit several record features of leaf and seed, and inflorescence size and leaves of great complexity. A marked ability to generate new roots allows them to be transplanted easily. As climbing plants they develop the longest unrooted stems in which there are, paradoxically, anomalous features of vascular construction compared with tree palms. It is here claimed that they are the world's longest lived trees because stem cells of several kinds remain active in differentiated tissues throughout the life of the palm. Absence of physiological dormancy may be related to this property, together with inability to withstand freezing temperatures that would cause irreversible cavitation of tracheary elements. This largely restricts them to the tropics, for which they are emblematic organisms. In these biological features palms are indeed unique organisms.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 5–14.     

Comparative floral structure and systematics in Cucurbitales (Corynocarpaceae, Coriariaceae, Tetramelaceae, Datiscaceae, Begoniaceae, Cucurbitaceae, Anisophylleaceae)

Floral structure, including morphology, anatomy and histology, was comparatively studied in representatives of all seven families of Cucurbitales as currently circumscribed by other authors based on molecular analyses and including Corynocarpaceae, Coriariaceae, Tetramelaceae, Datiscaceae, Begoniaceae, Cucurbitaceae and Anisophylleaceae. Three superfamilial clades are supported by floral structure: Tetramelaceae/Datiscaceae, Tetramelaceae/Datiscaceae/Begoniaceae and Corynocarpaceae/Coriariaceae. Anisophylleaceae appear most isolated in Cucurbitales, and show more similarities with Oxalidales, especially Cunoniaceae, although some features of interest are shared with other Cucurbitales and not Oxalidales. Tetramelaceae and Datiscaceae share dioecy, completely isomerous (but not regularly pentamerous) flowers (not in male Datiscaceae), only small sepals, lacking petals (not in male Octomeles). Tetramelaceae, Datiscaceae and Begoniaceae share the presence of numerous small ovules and seeds with a large‐celled surface, 2‐cell‐layered integuments, and a collar around the funicle by an extension of the outer integument. Corynocarpaceae and Coriariaceae share thick petals, unifacial stigmas, superior ovaries with a single, median, pendant syntropous ovule per carpel, and annular outer integuments with vasculature at the base. The four classical core families of Cucurbitales: Tetramelaceae, Datiscaceae, Begoniaceae and Cucurbitaceae (relationship unresolved, not retrieved as a clade as yet in molecular studies) share in various combinations androdioecy, basifixed and extrorse or latrorse anthers, trimerous gynoecia, bifurcate free carpel parts, an extended roof over the ovary formed by the ventral parts of the carpels, and parietal placentae. Trends of interest at the order level are unisexual flowers, thick, pointed petals (if present) that do not conform to the model in other rosids or basal core eudicots, a 2‐cell‐layered inner integument, which is delayed in development, and lacking or scant tanniferous tissues in flowers. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 145 , 129–185.