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The Jenynsia lineata species complex comprises J. lineata from Montevideo, Uruguay and Jenynsia multidentata, from coastal basins of Brazil, Uruguay and Argentina up to 1200 m a.s.l. Taxonomic divisions within this group were tested using three different species delimitation methods, which found the two existing names to be synonyms and revealed a new cryptic species. Jenynsia darwini sp. nov. is distinguished from all congeners by having a unique combination of character states, including the shape of the dorsal postcleithrum (three times higher than wide v. less than two times higher than wide) and female colour pattern in the half of the caudal peduncle with rows of chromatophores segmented in unaligned spots (v. aligned spots forming lines). The new species also differs from J. lineata by having 26 nucleotide substitutions in the mitochondrial gene cytochrome c oxidase I (coI). Phylogenetic analysis of the genus based on morphological characters proposed by previous studies corroborates monophyly of the subgenera Plesiojenynsia and Jenynsia, with the new species being allocated to the subgenus Jenynsia as the sister group of J. lineata.  相似文献   

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Yang ZL  Weiß M  Oberwinkler F 《Mycologia》2004,96(3):636-646
Four new species of Amanita, Amanita-ceae (Agaricales) are described from the eastern Himalaya and adjacent regions of southwestern China. Amanita altipes and A. parvipantherina are members of section Amanita, while A. orientifulva and A. liquii are representatives of section Vaginatae. They are compared with similar species and illustrated with line drawings.  相似文献   

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We developed a combined molecular and morphological approach to unravel complex variation at low taxonomic levels, exemplified by some arctic members of Potentilla. Twenty-one populations from Svalbard were analyzed for random amplified polymorphic DNAs (RAPDs) and 64 morphological characters to test the hypotheses that (1) the P. nivea complex (section Niveae) consists of three taxa (P. chamissonis, P. insularis, and P. nivea), (2) three "eco-morphotypes" in P. pulchella (section Multifidae) should be considered different taxa, and (3) P. insularis originated as an intersectional hybrid (Niveae × Multifidae). Twenty-two RAPD multilocus phenotypes were observed in the 136 plants analyzed based on 35 markers. Three fairly distinct groups of RAPD phenotypes were identified in the P. nivea complex based on multivariate analyses and an analysis of molecular variance (AMOVA; 77.6% among-group variation). The variation within the P. nivea complex was more or less continuous in multivariate analyses of the morphological data. We identified, however, several individual morphological characters that separated unambiguously among the three groups of RAPD phenotypes, revealing that these groups correspond to the previously hypothesized taxa. Many identical RAPD multilocus phenotypes were observed in the "eco-morphotypes" of P. pulchella, suggesting that its conspicuous morphological variation is caused by plasticity or by genetic variation at a small number of loci. The hypothesis of the hybrid origin of P. insularis was not supported by the RAPD data. Overall, very little RAPD variation was observed within populations of the four taxa (2.1-16.7% in AMOVA analyses; average genotypic diversity, D, was 0.10-0.30). We conclude that detailed, concerted analysis of molecules and morphology is a powerful tool in low-level taxonomy.  相似文献   

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报道生于蔷薇科植物枇杷Eriobotrya japonica叶片上的链格孢属一新种,对该种结合形态描述及分子系统学分析明晰其分类地位。命名为枇杷链格孢Alternaria eriobotryae。研究标本保藏于贵州大学植物病理学实验室(HGUP)和中国科学院菌物标本馆(HMAS)。  相似文献   

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A palynological study by LM and SEM was made of 26 taxa of Potentilla L. subg. Potentilla. It is more precise on material from 110 populations, mainly from the western Mediterranean. On the basis of morphometry, the subg. Potentilla can be said to have a stenopalynous nature, due to the absence of significant differences between the taxa studied and to the high degree of overlapping shown by their range of variation. With respect to ornamentation, which is striate, only P. rupestris pollen can be separately identified by a much more marked striation than the other species studied. An attempt was made to observe the taxonomic and phylogenetic relationships between the species of the natural groups of Potentilla on the basis of their pollen characters.  相似文献   

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A revision of the genus Tecoma in Bolivia based on the author's herbarium research and extensive field observations is presented. Species delimitation is re-evaluated, resulting in the recognition of only four species, one of which, T. beckii J. R. I. Wood, is described as new. Tecoma sambucifolia is treated as var. sambucifolia (Kunth) J. R. I. Wood of the widespread and variable T. stans (L.) Juss., as it can only be distinguished on the basis of minor morphological characters and is not as geographically restricted as has been supposed. Tecoma fulva (Cav.) D. Don is treated as a variable species extending from central Peru to Chile and northern Argentina with six subspecies: ssp. fulva , ssp. guarume (A. DC.) J. R. I. Wood, ssp. tanaeciiflora (Kränzlin) J. R. I. Wood, ssp. arequipensis (Sprague) J. R. I. Wood, ssp. garrocha (Hieron.) J. R. I. Wood, and ssp. altoandina J. R. I. Wood, the latter described as new. The differences between T. tenuiflora (A. DC.) Fabris and the Peruvian T. rosifolia Kunth are discussed. Hybrids are formally recognized in the genus for the first time, and the implications for the accepted corolla morphology and pollination syndromes are discussed. Maps illustrate the geographical distributions of the species. All taxa discussed in the paper are illustrated.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 143–172.  相似文献   

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This paper contributes to a revision of the genus Halectinosoma . Four new species are described, based on examination of ectinosomatid material from localities in western Europe, eastern Canada and the Arctic. Halectinosoma mandibularis sp. nov. is distinguishable from other species by the reduced setation of the mouthparts and enlarged mandibular gnathobase. Halectinosoma latisetifera sp. nov. bears an affinity with H. cooperatum but is easily distinguished by the shape of the setae on the female fifth leg. A species previously erroneously ascribed to H. finmarchicum (Scott) by several authors is described here as Halectinosoma kliei sp. nov. Halectinosoma gothiceps (Giesbrecht) is redescribed and the closely related Halectinosoma paragothiceps sp. nov. is described and distinguished from H. gothiceps . It is considered likely that some previous records of H. gothiceps are in error.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 453–475.  相似文献   

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A new species, Bellevalia juliana Bareka, Turland & Kamari (Asparagaceae) is described from E Kriti (Greece) and compared with other related taxa from Greece and the Mediterranean area. It is a member of B. sect. Bellevalia and a karyological study revealed a hexaploid karyotype with 2n = 6x = 24 chromosomes, illustrated here. The conservation status of the new species is assessed as Vulnerable (VU), according to IUCN criteria.  相似文献   

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Trichomes of 26 species of Alcea (Malvaceae) were investigated using light (LM) and scanning electron microscopy (SEM). The trichomes show a great micromorphological variation, which provides data useful for species delimitation in Alcea. Two basic types of trichomes could be distinguished in Alcea and allied genera: glandular and eglandular. The glandular trichomes could in turn be subdivided into two subtypes: capitate and clavate. The eglandular trichomes could be subdivided into five subtypes: simple, fascicled, stellate, fascicled-stellate and pluri-radiate. Characters of taxonomic interest are: trichome density (glabrous to dense), number of arms per trichome, orientation relative to the epidermal surface (appressed to erect) and presence/absence of a stalk. According to the results the species of Alcea can be divided into four informal groups based on trichome types. The results further support the exclusion of the annual Althaea species from the perennial ones and their close relationship to Malva. In addition, a close relationship between perennial Althaea and basal Alcea lineages is supported. Based on the evolutionary framework provided by recent molecular phylogenetic investigations, the following trends can be observed in the Malva alliance: long and narrow-armed trichomes are primitive in relation to short and thick-armed trichomes; dense indumentum coverage is primitive in relation to moderately dense or glabrous ones; presence of simple hairs on stem (particularly on leaves) is more advanced than their absence; spreading villous-stellate and fascicled trichomes are more advanced than appressed stellate ones. Clavate trichomes, which were found exclusively in a few species of Alcea, should be considered as a derived state in relation to capitate ones, and they may provide a synapomorphy for the crown group of Alcea.  相似文献   

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A population of putative hybrids between theendemic Rubus hawaiensis and naturalizedR. rosifolius was discovered inKpahulu Valley, on the island of Maui inthe Hawaiian archipelago. The goal of thisstudy was to molecularly characterize thisnatural hybridization event, investigate themode of hybridization, and determine the malefertility of the hybrid individuals. Bothmorphological and RAPD marker data indicatethat the putative hybrid individuals are theprogeny of R. rosifolius and R.hawaiensis. All 39 hybrid individuals sampledhad the chloroplast DNA haplotype of R.rosifolius. Thus hybridization appears to beasymmetric, with R. rosifolius acting asthe maternal parent. All hybrid individualsassessed for pollen stainability were sterile,and there was no evidence of backcrossing toeither parent. This result suggests thathybrids are of the first filial generation andthat variation among hybrids reflectsdifferences within the parental populations.Sympatric populations of R. hawaiensisand R. rosifolius occur on four islandsand six additional alien species of Rubusare naturalized and sympatric with R. hawaiensisin Hawai`i. Further investigationis merited to assess whether hybridization maypose a threat to the long term viability ofR. hawaiensis. This study highlights theincreasing frequency and negative consequencesof native-alien hybridization and theimportance of maintaining active alien speciescontrol programs in the Hawaiian Islands.  相似文献   

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The systematics of the genus Crataegus (Rosaceae) have been considered problematic owing to the fact that hybridization, introgression, polyploidy and apomixis may occur in this genus. A study of the Crataegus species from the Arab mountains, Sweida Province, Syria, has been undertaken based on both plastid DNA sequences ( trn L- trn F, psb A- trn H) and morphological data. In the investigated region, three morphologically distinguishable Crataegus species: C. azarolus var. aronia L., C.  ×  sinaica Boiss. ssp. sinaica and C. monogyna var. monogyna Jacq. were investigated. Crataegus azarolus can be clearly distinguished morphologically from C. monogyna by the colour, size and structure of fruits, the number of pyrenes, the flowering and ripening time, the density of thorns, the tree shape and also the leaf shape. According to our morphological data, in Syria, C.  ×  sinaica is variable and could represent a hybrid of C. azarolus  ×  C. monogyna ; the cpDNA sequence analysis showed sequences corresponding to C. monogyna as the plausible mother of the hybrid.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 255–263.  相似文献   

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Chromosome numbers in 80 populations belonging to 18 species of Potentilla L. subgen. Potentilla from the Iberian Peninsula and two of P. maura, a North African endemic taxon, have been counted. The basic number of chromosomes is always x = 7 and these chromosomes are small (between 1 and 2 μm). For three species, the number of chromosomes is reported for the first time and, for another six, this number has been established in Iberian representatives. Moreover, new ploidy levels have been obtained for P. hispanica and P. crantzii with regard to their entire distribution area, and in P. cinerea and P. neumanniana for the Iberian Peninsula. Some taxonomic, phylogenetic and phytogeographic comments are made for several species or groups of species from the West Mediterranean region. In 13 species only one ploidy level has been found, but six species have several ploidy levels. Seven ploidy levels occur in the investigated taxa. The frequency of each ploidy level represented within Iberian Potentilla is analysed and the data are compared with those available for taxa from the rest of the distribution area of the genus.  相似文献   

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Ectinosomatid material was examined from extensive collections around the British Isles and from several additional world localities and museum collections, permitting a revision of the genus Halectinosoma. This paper describes 12 morphologically similar species and erects five new species. H. sarsi (Boeck) is regarded as species incertae sedis, while H. sarsi sensu Sars (1904) is redescribed as H. pseudosarsi sp. nov.; H. sarsi sensu T. & A. Scott (1894) is synonymized with H. canaliculatum (Por). H. propinquum is regarded as a junior subjective synonym of H. chrystalli (T. Scott). H. clavatum (Sars) is resurrected, having previously been regarded as a synonym of H. brunneum (Brady). A key for the identification of females belonging to this group of species is provided.  相似文献   

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GOYDER, D. J., 1987. A revision of Arenaria section Plinthine (Coryophyllaceae). The systematics of Arenaria section Plinthine are reviewed and a classification is presented, based on detailed field and herbarium studies. Members of the section are found on the mountains of SW Europe and N Africa. Seven taxa are recognized within five species: A. alfacarensis, A. tetraquetra subsp. tetraquetra, A. tetraquetra subsp. amabilis, A. armerina, A. aggregata subsp. aggregata, A. aggregata subsp. erinacea , and A. querioides. Arenaria armerina and A. aggregata subsp. erinacea are extremely polymorphic and include minor morphological variants which have been treated as separate species in previous systematic treatments of the group.  相似文献   

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Noel H. Holmgren 《Brittonia》1987,39(3):340-344
Two new species ofPotentilla from the Intermountain West (U.S.A.) are described and illustrated here for the first time.Potentilla cottamii is known only from the higher quartzite slopes of the Pilot Range and the Raft River Mountains of western Box Elder Co., Utah and adjacent Elko Co., Nevada in the Great Basin. It most closely resemblesP. hyparctica, P. robbinsiana, andP. frigida, which may be its closest living relatives.Potentilla angelliae is known only from one collection from a subalpine meadow on Boulder Mountain of the Aquarius Plateau in southern Utah. It most closely resemblesP. crinita, P. subjuga, andP. bicrenata, the first of which is considered to be its closest relative.  相似文献   

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