Search results for "botany"
showing 10 items of 4586 documents
The Staminal Lever Mechanism in Salvia L. (Lamiaceae) - a Review
2003
Abstract: The genus Salvia encompasses about 900 species distributed world-wide. It is characterized by the famous staminal lever mechanism of the flower which is one of the best known examples of a nototribic pollination mechanism. We hypothesize that structure and functioning of the staminal levers play a major role as key structures in speciation. To cope with the complex evolutionary processes involved, a number of different methodological approaches are needed. The present paper summarizes the literature referring to structural and functional diversity, breeding systems, systematics and evolution in Salvia.
Phylogeny of Veronica in the Southern and Northern Hemispheres based on plastid, nuclear ribosomal and nuclear low-copy DNA
2010
The cosmopolitan and ecologically diverse genus Veronica with approximately 450 species is the largest genus of the newly circumscribed Plantaginaceae. Previous analyses of Veronica DNA sequences were in stark contrast to traditional systematics. However, analyses did not allow many inferences regarding the relationship between major groups identified, hindering further analysis of diversification and evolutionary trends in the genus. To resolve the backbone relationships of Veronica, we added sequences from additional plastid DNA regions to existing data and analyzed matching data sets for 78 taxa and more than 5000 aligned characters from nuclear ribosomal DNA and plastid DNA regions. The…
Revision of the plant bug genus Xenocylapus Bergroth (Hemiptera: Heteroptera: Miridae: Cylapinae), with a description of Henryfulvius gracilis – a ne…
2014
SummaryThe genus Xenocylapus Bergroth, 1922 is revised. Nine new species, Xenocylapus aculeatus sp. nov., X. aquilonius sp. nov., X. bicolor sp. nov., X. globulus sp. nov., X. heissi sp. nov., X. panamaensis sp. nov., X. serrulatus sp. nov., X. tenuis sp. nov., and X. waorani sp. nov., are described from Brazil, Honduras, Mexico, and Panama. New genus and species Henryfulvius gracilis gen. nov., sp. nov. is described from Ecuador. Illustrations of the male genitalia, color photographs of dorsal and lateral views of the adult of most species, scanning electron micrographs of selected structures of X. tenuis, and keys to species of the genus Xenocylapus are provided.
The systematics of Soldanella (Primulaceae) based on morphological and molecular (ITS, AFLPs) evidence
2002
Based on the observation of more than 6300 herbarium specimens and molecular (ITS, AFLPs) evidence, Soldanella is divided into 16 species and four subspecies. Soldanella angusta, S. oreodoxa and S. rugosa are described as new, and the circumscriptions of S. marmarossiensis, S. major, S. pusilla ssp. pusilla and S. hungarica are emended. Nine hybrid names are lectotypified. All non-hybrid taxa are described in detail and distribution maps are provided. Interspecific relationships are discussed on the background of morphological and molecular variation.
An inventory of the names of vascular plants endemic to Italy, their loci classici and types
2015
The census of the loci classici of 1,400 Italian endemic vascular plants (i.e. not thriving elsewhere with the exception of Corsica and Malta) is here presented and described. The effective place of publication of accepted names, basionyms and homotypic synonyms were identified and critically verified. This often resulted in some change in authorship attribution and, in seven cases, in validation problems (Asperula cynanchica var. lactea var. nov., A. lactea comb. nov., Biscutella laevigata subsp. raffaelliana subsp. nov., Ferulago nodosa subsp. geniculata comb. & stat. nov., Limonium tineoi comb. nov., L. usticanum sp. nov., Noccaea torreana comb. nov.). The geographic information on t…
Micromorphological approach to the systematics of Mediterranean Isoëtes species (Isoëtaceae, Lycopodiophyta): analysis of the megaspore surface
2012
Megaspore ornamentation is one of the few morphological characters used in the taxonomy of the genus Isoëtes. In the present work, we test the application of this character for distinguishing some Isoëtes species occurring in the Mediterranean: Isoëtes sicula, which according to some authors should be included as a variety in I. histrix, and the recently described I. todaroana, whose affinity with other taxa is currently unknown. Two additional species (I. duriei, I. velata) were also included in the analysis. The megaspores were studied using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy and chemical treatment. In all species, the megaspore surface is cove…
A reassessment of the sections of the genus Cytisus Desf. (Cytiseae, Leguminosae)
2006
Recent morphological and molecular research on Cytisus and allied genera has produced a great deal of new data relevant to systematics, which have not yet been incorporated into a consistent classification system of the genus. We have compared and evaluated recently published cladograms and phenograms based on morphological and molecular (nuclear and plastid DNA) characters. The genus Cytisus sensu lato, including Calicotome, Chamaecytisus, Chronanthus, and Lembotropis, appears to be monophyletic. A subdivision of the genus Cytisus in 13 sections is presented; one species, C. tribracteolatus, remains incertae sedis. A new section (C. sect. Dendrocytisus) and two new combinations for taxa in…
Evolution of the grapevine (Vitis viniferaL.) imprinted by natural and human factorsThis review is one of a selection of papers presented at the symp…
2007
This paper is concerned with vegetative reproduction, which is the only mode of propagation in cultivated grapevines. After a brief summary of the systematics of the Vitaceae the question of the nomenclature of cultivated grapevines is discussed. Intra-varietal variability is discussed using morphological and molecular characteristics. The origins of variation are presented: mutations, foreign nucleic acids, and memory of previous environmental conditions. Grapevines provide characteristic products, leading viticulturalists to make selections among the diversity observed in the vineyard, thus decreasing diversity. Grapevines interact with various environmental agents. One example, the natur…
A taxonomical study of the subtribe leontodontinae based on the distribution of phenolic compounds
1993
Abstract Evaluation of the phenolic constituents of five species belonging to the subtribe Leontodontinae (family Asteraceae) allowed the identification of ten flavonoid and eight phenolic acids by means of HPLC and other standard methods. The role of these compounds in relation to the morphological characteristics in the systematics of the subtribe is discussed.
Molecular phylogeny of Atripliceae (Chenopodioideae, Chenopodiaceae): Implications for systematics, biogeography, flower and fruit evolution, and the…
2011
Premise of the study : Atripliceae (Chenopodiaceae), including Atriplex (300 spp.) as the largest genus of the family, are an ecologically important group of steppes and semideserts worldwide. Relationships in Atripliceae are poorly understood due to obscure and potentially convergent morphological characters. Methods : Using sequence variation of two chloroplast markers ( rbcL gene, atpB-rbcL spacer) and one nrDNA marker (ITS) analyzed with BEAST, we investigated the systematics and biogeography of Atripliceae. We surveyed fl ower morphology and fruit anatomy to study the evolution of fland fruits in the tribe. Key results : Female fl owers with persistent foliar cover (the diagnosti…