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A new species, Limonium scopulorum (Plumbaginaceae), is described from the maritime cliffs of Alicante province, Spain (southeastern part of the Iberian Peninsula). This new taxon belongs to the group of Limonium delicatulum, which is highly diversified in the Mediterranean territories of the Iberian Peninsula. It is related to the Balearic species L. biflorum, though several leaf, floral and chromosomal features warrant its easy recognition. Molecular divergence, shown in previous studies, also supports its separate treatment. Major affinities and differences with other related taxa are discussed. Moreover, morphological, ecological, chorological, biogeographic features of the new taxon are discussed, and its conservation status is reported. An identification key is provided for Spanish taxa of the Limonium delicatulum group.  相似文献   

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报道新疆拟橙衣属地衣的6个分类单位。其中南方拟橙衣Fulgensia australis,荒漠拟橙衣F.desertorum和苔生拟橙衣F.schistidii为中国新记录种。在形态学、解剖学、化学及生态学方面对它们进行了简短的论述。此外,还提供了形态特征和内部解剖特征照片以及新疆种类的分种检索表。研究所用的标本采自托木尔峰、铁力买提达坂、阿尔金山和准葛尔盆地等,保存于新疆大学生命科学与技术学院地衣标本室。  相似文献   

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Leontodon palisiae sp. nov. occurring in the Iberian Peninsula, Morocco and the Canary Islands is described and illustrated. Cytological data as well as some preliminary results of self-incompatibility tests in L. palisiae are presented. A comparative carpological study of L. muelleri, L. palisiae and L. salzmannii using the SEM is made, and an identification key of these three species is provided. Two new combinations, L. muelleri ssp. trivialis comb. nov., from Morocco, and L. kralikii comb. nov., from Libya and Tunisia, are proposed. All taxa belong to the series Annui of sect. Kalbfussia in subgenus Oporinia. The basic chromosome number x=5 is here reported for the first time within the genus.  相似文献   

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A systematic revision for the species of Launaea Cass. in Egypt has revealed the presence of fourteen taxa belonging to 12 species, of which L. acanthodes (Boiss.) Kuntze is a new recorded. One new combination “L. fragilis subsp. tenuiloba (Boiss.) Zareh & Mohamed” is made. Achene diversity of the studied taxa of Launaea was studied using light and scanning electron microscopy. The taxonomic relationships between the studied taxa were discussed as well as SEM micrographs of achenes are provided. Synonyms and key for the identification of the investigated taxa based on morphological characters as well as notes on distribution are provided.  相似文献   

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The identification of macrophyte reference communities represents a significant challenge in Mediterranean zones, where few aquatic taxa exist compared to other regions of the world. In the highly seasonal rivers of Portugal, we explored the contribution of bryophytes to enhance the compositional and ecological characterization of reference conditions. We performed partitioning, classification, and ordination analyses and obtained eight groups of bryophytic assemblages explained by water availability and quality. Groups A, B, and H assemblages are type-specific of the inland areas of the northern eco-region, reflecting the neutral minerotrophic currents with summer low currents. Groups C and D are type-specific of acidic oligotrophic shifting currents dependent of precipitation events in the mountainous streams of the North Atlantic eco-region. Groups E, F, and G are widespread in continental northern, central, and southern zones in neutral and highly mineralized watercourses with seasonal dryness. We propose bryophytes as a tool in the characterization of the reference conditions for two main reasons: (i) many of the recorded taxa are capable of withstanding the natural seasonal desiccation, and (ii) the type-specific bryophytes have perennial life-strategies and can be assessed at any time of year as a support for other type-specific macrophytes in compositional assessments of reference conditions.  相似文献   

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利用扫描电子显微镜对车前科(P lantaginaceae)地黄属(Rehmannia)和崖白菜属(Triaenophora)8种植物成熟叶片的背面进行了观察。地黄属和崖白菜属的气孔都突出于叶表面,气孔类型均为无规则型;毛被有2种类型,即单列多细胞疏柔毛 单列多细胞腺毛和单列多细胞棉毛 单列多细胞腺毛。气孔和毛被在种间无明显的差异,不能作为分种依据,但毛被在属间具有明显的差异,具有一定的属间分类意义。  相似文献   

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TURLAND, N. J., 1992. Floristic notes from Crete. Phytogeographical and ecological notes are given for 24 taxa of vascular plants occurring on the south Aegean island of Crete. These cover infrequent, localized and endemic species and include five new records: Daphne gnidioides, D.jasminea, Fraxinus ornus, Hemarthria altissima and Teline monspessulana. The occurrence of Orobanche lavandulacea and Ranunculus velutinus is confirmed. A second site is reported for the extremely rare endemic Convolvulus argyrothamnos and additional sites for a number of other localized endemics are provided.  相似文献   

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New methods of sampling, preparing and identifying fossil wood fragments preserved in browncoal are presented and used to aid in reconstructions of the vegetation from the Miocene Lower Rhine Basin (Germany). The technique involves laboratory charring wood specimens followed by routine identification with reflected light microscopy. Problems concerning the taxonomic identification of the fossil wood are discussed. A list of taxa is presented for the Garzweiler Seam and the implications for reconstructing the Miocene palaeoenvironment are discussed with reference to ecological comparisons of extant taxa: the nearest living relative approach. Results indicate a dominance of conifer wood types, mostly representing members of the Taxodiaceae and Cupressaceae; extensive sampling is required of both small (macroscopic) and large fragments to obtain results comparable with palynological assemblages. Up to now, twenty-one taxa of gymnosperms and angiosperms have been recognized from the Garzweiler seam. Data obtained are compared with those from pollen analysis and corroborate the previously identified trend consisting of increasing concentrations of Taxodium towards the upper section of the seam.  相似文献   

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利用扫描电子显微镜对车前科(P lantaginaceae)地黄属(Rehmannia)和崖白菜属(Triaenophora)8种植物成熟叶片的背面进行了观察。地黄属和崖白菜属的气孔都突出于叶表面,气孔类型均为无规则型;毛被有2种类型,即单列多细胞疏柔毛+单列多细胞腺毛和单列多细胞棉毛+单列多细胞腺毛。气孔和毛被在种间无明显的差异,不能作为分种依据,但毛被在属间具有明显的差异,具有一定的属间分类意义。  相似文献   

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Changes in land use and the associated changes in land cover are recognized as the most important component of human-induced global change. Much attention has been focused on deforestation, but grasslands are among the most endangered ecosystems on Earth. The North American tallgrass prairie is a dramatic example, exhibiting a greater than 95% decline in historical area. Renewed interest in prairie conservation and restoration has highlighted the need for ecological indicators of disturbance and recovery in native systems, including the belowground component. The tallgrass prairie differs from the agricultural systems that have replaced it in having greater diversity and heterogeneity of resources, less physical soil disturbance (although other disturbances, such as fire and grazing, are prominent), and greater nitrogen limitation. Understanding the responses of nematode taxa to these characteristic differences is crucial to the development and improvement of community indices, but while knowledge of disturbance responses by individual taxa is accumulating, the level of necessary taxonomic resolution remains in question. Although nematode communities generally are better described for temperate grasslands than for other natural ecosystems, identification of sentinel taxa is further confounded by high levels of diversity, and both spatial and temporal heterogeneity.  相似文献   

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This study reports on 230 infrageneric lichenized and lichenicolous taxa from Barla Mountain, Isparta, Turkey and assesses the ecological features of the area using the distribution of the lichens in the region and their poleophoby and solar irradiation ecological indicator values. One lichenized fungus, Protoblastenia terricola, and one lichenicolous fungus, Zwackhiomyces dispersus, are recorded as new in Turkey and 194 taxa are reported for the first time from Barla Mountain. After this research, number of the lichenized and lichenicolous fungi taxa of Barla Mountain rose to 241. Based on assessments using the ecological indicator values, the area is dominated by natural or semi-natural and well-preserved habitats.  相似文献   

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Nir L. Gil-Ad 《Brittonia》1998,50(1):91-121
Viola subsect.Boreali-Americanae, confined to North America including northern México, has long been considered one of the most taxonomically difficult temperate groups of the angiosperms. Hybridization, followed in some localities by introgression, has made it difficult for systematists to discern the “core” species by using only standard macromorphological characters. Analyses that employed scanning electron microscopy (SEM) of seed coats and petal trichomes generated new characters. SEM of the surface of seeds of each of the orthospecies revealed a suite of primary and secondary sculpture characters unique to each species that are correlated with a suite of macromorphological characters. In a number of species, SEM of petal trichomes provided additional unique characters. SEM of the surface of seed coats enabled, also, the identification of instances of hybridization by revealing blends of structures of the primary and secondary sculpture typical of different orthospecies and instances of putative introgression by revealing deviations in surface structures from those typical of orthospecies. A procedure based on iterative examinations of macromorphology and micromorphology, which was developed in this research, enable the discernment of hybrids and putative introgressants. Combining the micromorphological and macromorphological data with ecological and phytogeographical data enabled the delimitation of sixteen orthospecies.  相似文献   

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Pollen morphology of selected taxa from the Hengduan Mountains, Southwest China are investigated in the present study. Forty eight taxa (flowering in the summer, 46 species and 2 varieties) of 43 genera belonging to 27 families were observed by light and scanning electron microscopy. Pollen morphology is described in detail. Two pollen shapes are mainly found in these species: subprolate to prolate (271%) and prolate (25%). Spheroidal, subspheroidal to subprolate, suboblate and tetrad shapes can also be found in some species. Aperture type is mostly tricolporate, with a percentage of 438, and also contains tricolpate, pantoporate, stephanocolpate, 3 colporoid, 6 colpate, monocolpate. The most common ornamentation is finely reticulate, with a percentage of 50. Other exine ornamentations, such as coarsely reticulate, finely granulate, smooth, spinulose are also observed. The palynological documentation of these species will provide the modern palynological basis for paleopalynological studies of the Quaternary Strata. On the basis of pollen morphology characters, identification features of some species in the same families were discussed according to the results of cluster analysis used by SPSS. The ecological significance was also discussed based on the ecological properties of these taxa.  相似文献   

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