Polyploidy in Aconitum subgenus Lycoctonum (Ranunculaceae)

Chromosome numbers and morphology in 22 populations belonging to 11 taxa of Aconitum subgenus Lycoctonum (Ranunculaceae) from China were studied. Some taxa were diploid, with 2 n  = 16, but four species and two varieties were found to be tetraploid, with 2 n  = 32. They are concentrated in the Hengduan Mountains region in south-west China, indicating that polyploidy could have played an important role in the speciation of the subgenus in this region, one of the areas of the world with a high concentration of endemic species. The relationships of some of the species are discussed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 343–353.     

Natural hybridization does not dissolve species boundaries in commercially important sea cucumbers

The study of species boundaries in areas of sympatry provides important insight into speciation processes. We investigated whether (i) two sympatric holothurians, Holothuria scabra and H. s. var. versicolor constituted species, and (ii) specimens of intermediate phenotype hybrids. Results from allozyme and 16S mtDNA sequence analyses indicated these two sea cucumbers to be distinct but young biological and phylogenetic species. Several private allozyme alleles existed and a Bayesian analysis grouped varieties into separate clusters. MtDNA sequences hardly varied within each taxon, and nine single bp changes were diagnostic between these two taxa. Allozyme allele frequencies in individuals of intermediate phenotype were intermediate to those of H. scabra and H. s.  var.  versicolor , most private alleles were present and heterozygote frequencies were higher than in either species. Ancestry coefficients modelled for these individuals were close to 0.5, indicating that the two taxa contributed equally to their genome. MtDNA sequences were identical to those of either species. We conclude that individuals of intermediate phenotype represent F1 hybrids. The presence of hybrids demonstrates that the opportunity for introgression exists, but is not realized, as backcrossing and introgression were not supported by the data. Thus, the genetic integrity of either holothurian species remains intact through an unknown postzygotic mechanism, possibly hybrid sterility.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 261–270.     

New or rarely reported chromosome numbers in taxa of subtribe Artemisiinae (Anthemideae, Asteraceae) from Mongolia

This study encompasses 25 chromosome counts of 18 species in the subtribe Artemisiinae (tribe Anthemideae) of the family Asteraceae, from Mongolia. Most (15 species) belong to Artemisia , the largest genus of the subtribe, whereas the others come from two genera very closely related to it: Ajania (two species) and Neopallasia (one species). Eleven counts are new reports, three are not consistent with previous reports and the remainder confirm scanty earlier information. The majority of the species have x  = 9 as their basic chromosome number, but there are some taxa with x  = 8. Ploidy levels range from 2 x to 6 x . The presence of B-chromosomes was detected in Ajania fruticulosa .  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 203–210.     

Delturinae, a new loricariid catfish subfamily (Teleostei, Siluriformes), with revisions of Delturus and Hemipsilichthys

A new subfamily, Delturinae, is described to accommodate the loricariid catfish genera Delturus Egenmann & Eigenmann, 1889 and Hemipsilichthys Eigenmann & Eigenmann, 1889, a clade recently demonstrated to be the sister group of all remaining loricariids except Lithogenes . The genus Hemipsilichthys is restricted to three species, H. gobio (Lütken, 1874), its sister species H. papillatus Pereira et al ., 2000, and H. nimius Pereira et al ., 2003. Relationships among species of Delturus were not resolved and a new species, D. brevis , is described from the Rio Jequitinhonha basin in eastern Brazil. The geographical distribution of Delturinae, exclusively on the south-eastern Brazilian Shield, indicates that south-eastern Brazil acts as either a refugium for basal loricariid taxa or a point of origin for the Loricariidae. Lectotypes are designated for D. parahybae Eigenmann & Eigenmann, 1889 and Plecostomus angulicauda Steindachner, 1877. Keys are presented for subfamilies of Loricariidae and for genera and species of Delturinae. Diagnoses are provided for all delturine clades and species.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 277–299.     

Checklist of the Caesalpinioideae (Leguminosae) of Equatorial Guinea (Annobón, Bioko and Río Muni)

This study provides a checklist of the Caesalpinioideae (Leguminosae) present in Equatorial Guinea, comprising 52 genera and 124 taxa. Seven species are known from Annobón, 33 from Bioko and 109 from Río Muni. The best represented genus is Senna with eight species. In addition, bibliographic references for Caesalpinioideae (Leguminosae) from Equatorial Guinea have been gathered and checked. Fourteen species are included based on literature records, because their distribution ranges suggest they may occur in Equatorial Guinea, 11 introduced species could be naturalized, and 45 taxa are recorded for the first time from the country. This represents an increase of over 35% in the floristic knowledge of Caesalpinioideae from Equatorial Guinea. A statistical summary is presented at the end of the checklist.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 541–562.     

A new diploid Hieracium (Asteraceae: Lactuceae) from Bulgaria

Hieracium kittanae Vladimirov, a new diploid (2 n  = 18) species restricted to a few gorges in the Central Rhodope Mountains, south Bulgaria, is described and illustrated. It occurs in crevices of limestone rock in shady to sunny places with high atmospheric humidity. Morphologically, it to some extent resembles taxa from the H. glaucinum and H. schmidtii groups, but is otherwise very distinct, without close relatives in the Rhodope and neighbouring mountains.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003 , 143 , 213−218.     

A new species of Heliosperma (Caryophyllaceae) from Serbia and Montenegro

Heliosperma oliverae Niketić & Stevanović is described from Mt. Prokletije in south-west Serbia and north-east Montenegro, together with an estimation of its ecological preferences and International Union for Conservation of Nature and Natural Resources (IUCN) threat status. A map and illustration are provided. It is compared with seven closely related Balkan endemic taxa: H. macranthum Panić, H. retzdorffianum K. Malý, H. tommasinii Vis., H. insulare Trinajstić, H. chromodontum (Boiss. & Reuter) Juratzka, H. intonsum (Greuter & Melzh.) Niketić & Stevanović, and H. nikolicii (Seliger & T. Wraber) Niketić & Stevanović. An amended key to species and a table showing differences from the related Balkan taxa are also provided.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 55–63.     

Canarian land snail diversity: conflict between anatomical and molecular data on the phylogenetic placement of five new species of Napaeus (Gastropoda, Pulmonata, Enidae)

Five new species of land snail (family Enidae) are described from La Gomera (Canary Islands) of which the majority, on the basis of anatomy alone, could be incorporated within a new supraspecific taxon. In addition to the morphological study of these new species, a region of the 16S mitochondrial gene is sequenced from three of the new species and a range of species of Napaeus from within its two subgenera ( Napaeinus and Napaeus ) . There is a disparity between the morphological and preliminary molecular phylogenetic data. Possible explanations for this conflict are discussed, as well as the evolutionary relationships among these different taxa, and it is suggested that this group may be an excellent model for further studies of adaptation and diversification.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 169–187.     

Sexual dimorphism in scale rugosity in sea snakes (Hydrophiidae)

Some aquatic taxa (fishes, snakes) exhibit a puzzling form of sexual dimorphism: males have a more rugose body surface than do conspecific females. As a first step towards understanding the biological significance of this phenomenon, the nature and correlates (sex, size, body condition, season, and latitude) of scale rugosity was quantified in preserved museum specimens of four species of sea snakes (Family Hydrophiidae): Astrotia stokesii , Emydocephalus annulatus , Hydrophis elegans , and Lapemis hardwickii . Males are more rugose than conspecific females in all four taxa, on ventral as well as dorsal scales. The position of rugosities on the body differs among species. For example, rugosities are found over the entire body in E. annulatus , but are concentrated anteriorly in L. hardwickii and posteriorly in H. elegans . Females possess rugosities that are similar to those of conspecific males, but smaller (in female E. annulatus , they are visible only with scanning electron microscopy analysis). The degree of male rugosity varies seasonally in at least two species ( E. annulatus , L. hardwickii ), being most pronounced during the winter breeding season. Thus, the transition from terrestrial to aquatic life in proteroglyphous snakes has been accompanied both by an increase in overall rugosity, and by a seasonally labile sex-specific elaboration of this trait.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 343–354.     

Latitudinal and ecological correlates of morphological variation in Galaxias platei (Pisces, Galaxiidae) in Patagonia

We examined the morphological variability (23 morphometric traits) among individual Galaxias platei ( N  = 380) collected from 20 postglacial lakes in the southern Andes. The lakes were chosen to cover the latitudinal range of the species in Patagonia. Diet examined for a subset of these fish ( N  = 261) collected during the summer months (January through March), differed among river basins but there were no clear latitudinal trends in the consumption of any prey type. Diet may, however, have partially shaped morphology, as pelvic measures were negatively correlated with consumption of amphipods. Substantial differentiation among populations was observed, primarily in the shape and dimensions of the head, in caudal morphology and in fin length. Our results indicate that the morphology of G. platei varies with latitude, and may be related to risk of predation and diet.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 69–82.     

Chromosome numbers and karyotypes of South American species and populations of Hypochaeris (Asteraceae)

One hundred and thirty-seven new chromosome counts are reported from 104 populations of 26 native South American taxa of Hypochaeris (Asteraceae, Lactuceae), together with two invasive Mediterranean species: H. glabra and H. radicata . First reports are provided for seven taxa ( H. alba , H. cf. eremophila , H. caespitosa , H. hookeri , H. parodii , H. patagonica and H. pinnatifida ) and one new ploidy level is reported (diploid for H. incana , so far known only as a tetraploid). Including the results of this study, the chromosomes of 39 of the c . 50 Hypochaeris species known from the New World have now been counted. Most species are diploid with 2 n  = 2 x  = 8 and have bimodal, asymmetrical karyotypes. Tetraploidy (2 n  = 4 x  = 16) is reported here for the first time in H. caespitosa . Infra-specific polyploidy (probably autopolyploidy) is reported in H. incana and H. taraxacoides , both cases including infra-populational cytotype mixtures (2 x and 4 x ). Polyploidy is now known from eight South American Hypochaeris species ( c . 16%). Basic karyotype analyses allow the placement of the newly counted taxa into previously proposed but slightly modified groupings and provide the framework for further molecular cytogenetic analyses. The reported findings suggest that chromosomal change in South American Hypochaeris , in contrast to Old World species, has not involved aneuploidy, but polyploidy and/or more subtle changes in chromosome length, perhaps via satellite DNA amplification/deletion or activity of retroelements, and rDNA reorganization.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 49–60.     

A revision of Cerdia (Caryophyllaceae)

Cerdia is a poorly understood genus of minute cushiony plants endemic to Mexico that is traditionally placed in subfamily Paronychioideae, tribe Polycarpeae (Caryophyllaceae). Morphological observations and phylogenetic analysis of ITS DNA sequences were carried out to determine the number of species, heretofore controversial, that constitute the genus as well as its position within Caryophyllaceae. Samples of Cerdia were collected through its entire range of distribution and together with previous specimens were used in morphological analyses. Nineteen terminal taxa were considered in a phylogenetic analysis with representatives of the different lineages in Caryophyllaceae. Results indicated that Cerdia is a monotypic genus, including only one variable species, C .  virescens , but its phylogenetic affinities remain doubtful.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 1–13.     

Chromosome numbers in the tribe Anthemideae (Asteraceae) from north-east Anatolia

Twenty-two chromosome counts of 19 taxa in the tribe Anthemideae of the family Asteraceae are reported from north-east Anatolia, Turkey. The taxa belong to the subtribes Achilleinae (four Achillea taxa), Anthemidinae (five Anthemis taxa), Artemisiinae (two Artemisia species), Leucantheminae (one Lecanthemum species), Matricariinae (two Tripleurospermum species) and Tanacetinae (five Tanacetum taxa). Six counts are new reports, seven are not consistent with previous counts, and the remainder are confirmations of very limited previous data. Most of the populations of Anthemideae studied have the basic number x  = 9, with ploidy levels ranging from 2 x to 7 to 8 x , but dysploidy is also present, with one diploid species, Artemisia austriaca , having x  = 8.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 203–211.     

Comparative vegetative anatomy and systematics of the Oncidiinae (Maxillarieae, Orchidaceae)

Subtribe Oncidiinae comprises a vegetatively heterogeneous assemblage of species that has persistently been incapable of organization. Anatomy was considered to be a possible means to resolve the perplexity of relationships amongst the constituent taxa. The consistent occurrence of a foliar hypodermis, homogeneous mesophyll, conical silica bodies in stegmata, and ubiquitous fibre bundles in leaves provides a matrix for linking the taxa, as do the parenchymatous pith and O-thickened endodermal cell walls in roots. However, the strict consensus of the 40 genera studied was completely unresolved, suggesting that vegetative characters alone are insufficient to assess the relationships amongst these taxa, a conclusion also reached for the remainder of Maxillarieae.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 91–107.     

Genetic variation within and between Iliamna corei and I. remota (Malvaceae): implications for species delimitation

Iliamna corei and I. remota are classified as endangered species; however, their designation as separate species has been questioned. In order to address this problem, intersimple sequence repeat (ISSR) data were generated to examine patterns of genetic differentiation within and between these two taxa. ISSRs were used to screen individuals for genetic diversity of I. corei from the single known natural population and two garden populations, and individuals of I. remota from the six natural populations and four garden populations. Using ten primers, 140 informative markers were generated. Ninety-four percent of loci detected revealed polymorphisms. Cluster analysis (neighbour-joining, NJ) revealed that the two species are genetically distinct and that the Illinois populations of I. remota were genetically distinct from the Virginia populations of I. remota . Ordination by Principal Coordinate Analysis (PCoA) supported the findings of the NJ, with a separation of I. corei and I. remota . Analysis of Molecular Variance (AMOVA) revealed that the majority of variation detected was within populations, which is consistent with other self-incompatible plants. The results indicate a correlation between the geographical distributions of the species and gene flow.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 345–354.     

Festuca inops and Festuca gracilior (Poaceae): are they two different species?

According to current systematics, Festuca inops and F. gracilior are two distinct species. However, they are hardly distinguishable from each other on the basis of their morphological characters. Festuca inops is considered a diploid species endemic to Italy, while F. gracilior has a discontinuous distribution area, apparently related to chromosomal levels: diploid populations in Italy and south-east France, tetraploid populations in north-east Spain. The diploid populations of both taxa from Italy and south-east France are investigated in the present study. Nearly 1000 exsiccata were examined and morphometric analysis was carried out on macro- and micromorphological features of 119 specimens (including type-specimens) and on 20 natural populations (including loci classici ). All these data showed that the two species should be referred to a single taxon, for which the rank of species seems to be appropriate. This result is supported by karyological, ecological and chorological data and was confirmed by the results of ISSR analysis. According to nomenclatural rules, the legitimate name for the species is Festuca inops De Not.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 239–258.     

Two new species of Lessingianthus (Vernonieae, Asteraceae) from the Brazilian highlands

Two additional species of Lessingianthus , L. bakerianus and L. lanuginosus , from the campo cerrado vegetation of central Brazil, are described and illustrated. The first species is characterized by the presence of capitula arranged in groups, nine to 12 florets per head, leaves sessile, oblong to ovate leaf blades with the lower surface densely lanate, sparsely villous on the main veins. It has certain resemblance to L. syncephalus (Sch. Bip. ex Baker) H. Rob. and L. brevipetiolatus (Sch. Bip. ex Baker) H. Rob., which present petiolate leaves and leaf blades lanceolate, cuneate or attenuate at the base. L. lanuginosus is superficially similar to L. buddleiifolius (Mart. ex DC.) H. Rob., but differs in having smooth stems, woolly indumentum, smaller heads and the largest leaves disposed at the middle of the stem.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 150 , 487–493.     

Molecular evidence for repeated hybridization events involved in the origin of the genus × Crepidiastrixeris (Asteraceae) using RAPDs and ITS data

We investigated the hybrid origin of × Crepidiastrixeris denticulato-platyphylla using RAPDs and ITS sequence data. The putative parents Paraixeris denticulata and Crepidiastrum platyphyllum represent separate species, irrespective of geographical origin. The occurrence of species specific RAPD markers from P. denticulata and C. platyphyllum in × C. denticulato-platyphylla established unambiguously a hybrid origin between the two taxa. This was in line with the occurrence of a combination of morphological characters such as plant habit and floret numbers. The parent taxa differed from each other by 7 nucleotide substitutions and 2 indel events in the ITS region. The hybrids showed sequence additivity and most likely represent F₁ plants, with the exception of two plants which were of possible F₂ origin, possessing either the ITS sequences of one parent only, or one predominant ITS type. The hybrids occurred in two out of three localities where the parents occurred sympatrically. This fact, together with the short life-span of the plants, suggests that × C. denticulato-platyphylla exists as a result of repeated, frequent hybridization between the parent species.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 333–343.