Generic delimitation and a new infrageneric system in the genus Holcoglossum (Orchidaceae: Aeridinae)

Based on herbarium and field observations, we confirm the generic delimitation of Holcoglossum and present a new infrageneric system for the genus. Our work supports Holcoglossum as a natural group including H. amesianum (Rchb.f.) Christenson and H. subulifolium (Rchb.f.) Christenson. The new infrageneric system of Holcoglossum includes two subgenera: Holcoglossum subgen. Brachycentron subgen. nov. and Holcoglossum subgen. Holcoglossum , the latter comprising two new sections, Holcoglossum sect. Holcoglossum and Holcoglossum sect. Sorotylos .  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 465–468.     

Taxonomic problems in Carthamus (Asteraceae): RAPD markers and sectional classification

Recent molecular studies have clarified the problem of the generic limits of Carthamus . However, taxonomic problems remain in the sectional classification: section Carthamus was confirmed as a natural group, but molecular phylogenies based on DNA sequences did not resolve the other sections, resulting in a confusing conglomerate. A survey based on RAPD markers has been carried out in this conflicting group of sections, with the aim of evaluating the usefulness of these markers at the section and species levels. On the basis of the results, correlated with morphological and karyological characters, some recommendations are made in relation to the taxonomy of Carthamus . The number of sections is reduced from five to two: section Thamnacanthus is currently classified as a different genus, Phonus ; section Carthamus s.s. is retained in its present delimitation, and section Atractylis is redefined, including current sections Atractylis , Lepidopappus and Odontagnathius . The commonly accepted treatment of some taxa as subspecies is not well founded, and C. alexandrinus , C. creticus , C. tenuis and C. turkestanicus should be considered as independent species. Our results confirm that methodological problems posed by RAPD markers can be avoided by careful laboratory procedures and appropriate data analyses; they also suggest that this kind of marker is useful at low taxonomic levels and is, furthermore, complementary to DNA sequence analysis.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 375–383.     

和田沙漠玫瑰品种系统发育关系初步研究

该研究基于DNA分子数据分析和田沙漠玫瑰品种与丰花玫瑰、紫枝玫瑰、大马士革玫瑰品种的关系,构建和田沙漠玫瑰的系统发育关系,以探讨其杂交起源.结果表明:(1)和田沙漠玫瑰具有独特的遗传组成,品种内遗传距离(0.017±0.003)小于品种间的遗传距离(分别为0.029±0.005、0.024±0.004、0.022±0....     

Morphological analysis, phylogenies and classification in Velloziaceae

A morphological (non-molecular) cladistic analysis of the Velloziaceae is presented. The terminal taxa are 47 species of Velloziaceae plus four taxa as outgroups: Acanthochlamys bracteata (Acanthochlamydaceae), Encholirium scrutor (Bromeliaceae), Thoracocarpus bissectus (Cyclanthaceae) and Pandanus racemosus (Pandanaceae). The species of Velloziaceae sampled represent a significant proportion of the morphological diversity of the family, including all recognized genera and sections. The analysis revealed two major groups within Velloziaceae, supported mainly by stomata, vascular bundles in the pedicel, aquiferous tissues, filaments, anthers, pollen, stigma, seeds, ploidy and chemical characters. Comparison between this and the previous phylogenetic hypotheses for Velloziaceae, together with the two conflicting current classifications, suggests that there is incompatibility concerning the support of current genera and sections. The only three groups supported in all phylogenies are Barbacenioideae sensu Menezes (= Barbacenia sensu Smith & Ayensu), Xerophyta sect. Barbacenioides and Xerophyta sect. Xerophyta sensu Smith & Ayensu.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 157–173.     

A morphometric and molecular study in Tortula subulata complex (Pottiaceae, Bryophyta)

Specimens belonging to Tortula subulata complex ( T. inermis , T. mucronifolia and T. subulata ) were analysed using a combination of morphometric methods based on quantitative characters [principal component analysis (PCA), discriminant analysis (DA); 76 samples)] and molecular methods (ITS1 – 5.8S rRNA gene and ITS2; 47 samples) to assess patterns of morphological and molecular differentiation within this complex of taxa. The study shows that four species can be recognized: T. mucronifolia , T. subulata , T. inermis and T. subulata var. angustata with bistratose border, which is elevated to the species rank as T. schimperi nom. nov. The most valuable quantitative characters for identification of these species are the strata number of the marginal laminal cells, the ratio of middle marginal laminal cell width/middle marginal laminal cell length, basal membrane of peristome length, middle laminal cell width and papillae number on the middle laminal cells. The internal transcribed spacer (ITS) data suggest that this group of taxa is not monophyletic, T. mucronifolia being close to Protobryum bryoides (= Tortula protobryoides ). The remaining species seem to be a monophyletic group, T. schimperi being the sister group of the clade composed by T. inermis and T. subulata . T. subulata is considered to be of high morphological variability, for which ITS sequences did not resolve the internal relationships.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 333–350.     

A new species of Acantholimon Boiss. sect. Glumaria Boiss. (Plumbaginaceae) from Elazığ, Turkey

A new species, Acantholimon evrenii sp. nov. is described and illustrated for the first time in sect. Glumaria from Turkey. The species is confined to B7 Elazığ in East Anatolia where it grows on rocky mountain steppes. The diagnostic morphological characters from closely related species are given, along with a discussion dealing with its taxonomic relationship. Its conservation status is indicated. A revised key is also provided for the Acantholimon species with heterophyllous leaves, two or more flowered and four or more bracteated spikelets.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 351–356.     

Conflicting patterns of genetic and morphological variation in European Gentianella section Gentianella

Genetics in European Gentianella Moench sect. Gentianella were investigated using internal transcribed spacer (ITS) nrDNA, trn L-F cpDNA and Amplified Fragment Length Polymorphisms (AFLP) fingerprint data to analyse relationships within the section. Both a cladistic and a phenetic approach, as well as nonhierarchical analysis (PCA) and partitioning of molecular variance (AMOVA), were used. Sequence data did not resolve groups within the section. They reflected, however, geographical isolation between central European and eastern Carpathian ( G. lutescens and G. bulgarica ) as well as Caucasian samples ( G. caucasea ). AFLP data revealed a strong differentiation within G. germanica between populations of the Alps and north-western middle Europe, although there is hardly any morphological differentiation of taxonomic significance. Morphological similarities between G. aspera and G. pilosa were not reflected in genetics, and no support was found for G. aspera . Genetic similarities were not in line with morphology in G. lutescens and G. bulgarica . AFLP data only partly resolve relationships among taxa. High genetic similarities, as well as partitioning of molecular variance among taxa/populations of eastern middle Europe ( G. austriaca , G. bohemica , G. germanica , G. stiriaca ) and intermediate morphological characters in G. bohemica and G. stiriaca , might indicate reticulate evolution. The overall low sequence divergence within the section points to a very young origin of all taxa.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 175–187.     

AFLP markers as a tool to reconstruct complex relationships: A case study in Rosa (Rosaceae)

The genus Rosa has a complex evolutionary history caused by several factors, often in conjunction: extensive hybridization, recent radiation, incomplete lineage sorting, and multiple events of polyploidy. We examined the applicability of AFLP markers for reconstructing (species) relationships in Rosa, using UPGMA clustering, Wagner parsimony, and Bayesian inference. All trees were well resolved, but many of the deeper branches were weakly supported. The cluster analysis showed that the rose cultivars can be separated into a European and an Oriental cluster, each being related to different wild species. The phylogenetic analyses showed that (1) two of the four subgenera (Hulthemia and Platyrhodon) do not deserve subgeneric status; (2) section Carolinae should be merged with sect. Cinnamomeae; (3) subsection Rubigineae is a monophyletic group within sect. Caninae, making sect. Caninae paraphyletic; and (4) there is little support for the distinction of the five other subsections within sect. Caninae. Comparison of the trees with morphological classifications and with previous molecular studies showed that all methods yielded reliable trees. Bayesian inference proved to be a useful alternative to parsimony analysis of AFLP data. Because of their genome-wide sampling, AFLPs are the markers of choice to reconstruct (species) relationships in evolutionary complex groups.     

A revision and phylogenetic analysis of Stapeliopsis (Apocynaceae)

A survey of morphological characters is carried out for Stapeliopsis . The information obtained from this is combined with molecular data from the plastid trn L-F DNA region and ITS1 of the nuclear encoded 18S−26S rRNA cistron, to obtain a hypothesis of the evolutionary relationships among the species. It is shown that Stapeliopsis is monophyletic in a combined molecular and morphological analysis. Stapeliopsis is sister to a clade containing Huernia , Orbea and Tromotriche . The species of Stapeliopsis group into two clades. One contains S. khamiesbergensis , S. neronis and S. urniflora , and this is highly supported. The remaining species fall into an unsupported clade in which S. exasperata is sister to the others. The genera Hermanschwartzia Plowes and Neopectinaria Plowes are rejected. It is shown that a synapomorphy for Stapeliopsis is the laterally flattened inner corona-lobes, which touch the anthers only at their bases. Eight species of Stapeliopsis are recognized, with no subgeneric divisions.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 125–155.     

Molecular phylogeny of the genus Philodendron (Araceae): delimitation and infrageneric classification

The genus Philodendron (Araceae) is a large neotropical group whose classification remains unclear. Previous classifications are based on morphological characters, mainly from the inflorescence, flower and leaf shape. The classification by Krause, with few modifications, is still the most commonly used system. To examine phylogenetic relationships in the genus, two ribosomal DNA nuclear markers, internal transcribed spacer (ITS) and external transcribed spacer (ETS), and the chloroplast intron rpl 16, were sequenced and analysed for more than 80 species of Philodendron and its close relative Homalomena . According to the resulting phylogeny, the genus Homalomena may be paraphyletic to the genus Philodendron . The inclusion of the American Homalomena species within the genus Philodendron might resolve this taxonomic problem. All three subgenera of Philodendron were revealed as monophyletic. Below the subgeneric level, the groups obtained in our phylogeny globally correspond to sections recognized in previous classifications. Among the morphological characters used by previous taxonomists to build their classifications, and which we optimized onto one of the most parsimonious trees, most characters were found to be homoplasious. However, leaf shape, characteristics of the sterile zone on the spadix and venation patterns are useful for delimiting subgenera and sections within the genus.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 13–27.     

The utility of morphological characters in gastropod phylogenetics: an example from the Calyptraeidae

Organismal taxonomy is often based on a single or a small number of morphological characters. When they are morphologically simple or known to be plastic, we may not have great confidence in the taxonomic conclusions of analyses based on these characters. For example, calyptraeid gastropod shells are well known for their simplicity and plasticity, and appear to be subject to frequent evolutionary convergences, but are nevertheless the basis for calyptraeid taxonomy. In a case like this, knowing how the pattern of relationships inferred from morphological features used in traditional taxonomy compares to the patterns of relationships inferred from other morphological characters or DNA sequence data would be useful. In this paper, I examine the relative utility of traditional taxonomic characters (shell characters), anatomical characters and molecular characters for reconstructing the phylogeny of calyptraeid gastropods. The results of an ILD test and comparisons of the recovered tree topologies suggest that there is conflict between the DNA sequence data and the morphological data. Very few of the nodes recovered by the morphological data were recovered by any other dataset. Despite this conflict, the inclusion of morphological data increased the resolution and support of nodes in the topology recovered from a combined dataset. The RIs and CIs of the morphological data on the best estimate topology were not any worse than these indices for the other datasets. This analysis demonstrates that although analyses can be misled by these convergences if morphological characters are used alone, these characters contribute significantly to the combined dataset.  © 2003 The Linnean Society of London . Biological Journal of the Linnean Society , 2003, 78 , 541–593.     

Pollen morphology of Dioscorea (Dioscoreaceae) and its relation to systematics

This paper adds new data on the pollen and orbicule morphology of 61 Dioscorea L. (Dioscoreaceae) species to the survey of Schols et al . (2001). The results indicate that pollen characters may be significant in infrageneric systematics in Dioscorea . Pollen and orbicule characters are described based on observations with light microscopy, and scanning and transmission electron microscopy, and are critically evaluated and discussed in the context of existing hypotheses of systematic relationships within the genus. Pollen is mostly disulculate (sometimes monosulcate) with a perforate, microreticulate, striate, gemmate, rugulate, or cerebroid perforate sexine. The basal section Stenophora is one of the few sections with monosulcate pollen. Brachyandra , Cardiocapsa , and Seriflorae , three Malagasy sections, are characterized by striate pollen. Pollen morphology strongly supports section Enantiophyllum as a monophyletic group. The correlation between pollen size and tuber type, as suggested previously by P. Su (1987), is confirmed by our data. As found in our earlier survey, orbicules in Dioscorea are mostly spherical with a smooth or spinulose surface.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 375–390.     

Revision of the genus Clathrina (Porifera, Calcarea)

The genus Clathrina has one of the most difficult systematic arrangements in the Porifera, Class Calcarea. Few morphological characters can be used to describe its species, and the systematics and the geographical distribution of its species have changed several times, according to the point of view of the systematists. 'Lumpers' consider that clathrinas are morphologically plastic, while 'splitters' believe that even slight morphological differences should be considered sufficient to distinguish between species. The morphology of several specimens/species of Clathrina , including the type species, when possible, was studied and used to produce the first revision of this genus. Using results obtained from previous morphological and molecular studies, the morphological characters were chosen and analysed in all studied specimens. In total, 43 species were found, nine of which are new to science. These results agree with the viewpoint that morphological characters such as type and distribution of spicules, size of actines, spines, anastomosis of the cormus, organization of the osculum and presence of granules in cells, are useful when establishing the taxonomy of the genus.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society , 2003, 139 , 1−62.     

Integrative taxonomy in two free-living nematode species complexes

Integrative taxonomy considers species boundaries from multiple, complementary perspectives, with the main objective being to compare the observed data against the predictions of the methodologies used. In the present study we used three methods for delineating species boundaries within the cosmopolitan nematode species Rhabditis ( Pellioditis ) marina and Halomonhystera disjuncta . First, phylogenetic relationships among molecular sequences from the mitochondrial cytochrome oxidase c subunit 1 gene (COI), and from two nuclear regions, internal transcribed spacer (ITS) and D2D3, were analysed. Subsequently, multivariate morphometric analysis was used to investigate whether concordant molecular lineages were also morphologically distinct. When morphological differences were found, typological taxonomy was performed to identify fixed or non-overlapping characters between lineages. Interbreeding experiments were conducted between the two closest related lineages of R . ( P. ) marina to investigate potential reproductive isolation. This integrative approach confirmed the presence of several species within each nominal species: molecular lineages were concordant across two independent loci (COI and ITS), and were characterized by significant morphological divergence. Most lineages were also detectable in the D2D3 region, but were less resolved. The two lineages investigated in our study did not produce offspring. Our results highlight that classical taxonomy grossly underestimates species diversity within the phylum Nematoda.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 737–753.     

Galápagos' Opuntia (prickly pear) cacti: extensive morphological diversity, low genetic variability

Due to the pronounced morphological variation and geographical distribution of Galápagos' Opuntia cacti, numerous hypotheses have been advanced regarding their radiation, diversification, and classification. The currently accepted classification is based on morphology and recognizes six species and fourteen varieties, but the plasticity of many of the characteristics renders any morphological taxonomy problematic. Our analysis of previously published morphological data agrees only partially with the current classification. We present the first molecular phylogeny of these plants. Multiple DNA sequences indicate little genetic distinction among the currently identified species, despite restricted gene flow and limited long distance dispersal within the archipelago. No clear relationship exists between morphological and genetic differences. These results suggest that both molecular and morphological data should be used in conservation planning.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 451–461.     

Psephellus turcicus sp. nov. (Asteraceae), a new chasmophyte species from central Anatolia, Turkey

A new species, Psephellus turcicus A.Duran & Hamzaoğlu (Asteraceae) in sect. Psephelloidei (Boiss.) Wagenitz & Hellwig is described and illustrated from Anatolia, Turkey. The species grows on limestone crevices in Kazankaya Canyon (A5 Yozgat) in central Anatolia. A neo-endemic confined to Kazankaya Canyon, it is closely related to Psephellus psephelloides (Freny & Sint.) Wagenitz. Diagnostic morphological characters from closely similar taxa are discussed, and arranged in a key of Turkish similar Psephellus Cass. The ecology, biogeography and conservation status of the species are also presented. Achene surface morphology of P. turcicus and P. psephelloides are examined by SEM. The geographical distribution of the new species and other related species is mapped.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 495–500.     

Taxonomic notes on the genus Crataegus (Rosaceae) in Turkey

The Turkish Crataegus taxa were investigated using morphological, palynological, and anatomical characters. A new series ( Crataegus Section Crataegus Series Peshmenia ), two new species ( Crataegus peshmenii and Crataegus christensenii ), and one variety ( Crataegus rhipidophylla var. kutahyaensis ) are described. Furthermore, Crataegus  ×  browicziana has been assigned to Crataegus rhipidophylla with a new status. Illustrations of the described taxa and their distribution map are also given. The lectotype for Crataegus yaltirikii is designated here.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 231–240.