Search results for "Isoëte"

showing 3 items of 3 documents

Isoëtes sabatina (IsoëtaceaeLycopodiophyta), a new aquatic species from central Italy

2013

The new species Isoetes sabatina is described and illustrated. Morphological, anatomical, and ecological characters are given. It differs from the similar I. echinospora by several characters, such as megaspore ornamentation and size, microspore size, velum extension and form, and also for its ecology. A table showing the main differential characters of the new species compared with those of the other European aquatic species is presented. So far, the species is known from a single locality (Bracciano Lake, central Italy), having a peculiar ecology and within the Mediterranean bioclimate.

Mediterranean climatebiologyEcologySettore BIO/02 - Botanica SistematicaPlant Sciencebiology.organism_classificationIsoëtesLycopodiophytaAquatic speciestaxonomyIsoetaceae Isoetes Italy Lycopodiophyta Mediterranean region taxonomyItalyIsoetesIsoetaceaeTaxonomy (biology)Isoëtaceae; Isoëtes; Italy; Lycopodiophyta; Mediterranean region; taxonomyLycopodiophytaMegasporeMediterranean regionEcology Evolution Behavior and SystematicsIsoëtaceae
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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…

SystematicsbiologyIsoetes histrixSettore BIO/02 - Botanica SistematicaPlant Sciencebiology.organism_classificationSettore BIO/01 - Botanica GeneraleTaxonSEM energy-dispersive X-ray spectroscopy (EDS) Sicily siliceous coating Isoetes Isoëtes duriei Isoëtes histrix Isoëtes sicula Isoëtes todaroana Isoëtes velataIsoetesBotanyIsoetaceaeTaxonomy (biology)LycopodiophytaMegasporeEcology Evolution Behavior and Systematics
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The genus Isoëtes L. (Lycophyta, Isoëtaceae): Synthesis of karyological data

2001

Summary A synthesis of relevant karyological data regarding the genus Isoetes is given, with an up-to-date check list of chromosome numbers including 152 records referring to 67 taxa (62 species and 5 infraspecific taxa) and 16 hybrids. Total of different chromosome counts (considering two or more cytotypes for certain taxa, excluding hybrids) is 80. Probable base number is x = 11, even though x = 10 and x = 12 have been proposed for certain species. On the basis of data here summarized, the mean percentage of polyploidy is 61.2%; 31 taxa are diploids (38.8%), 28 are tetraploids (35.0%), 8 are hexaploids (10.0%), with a few species each which are tri-, penta-, octo-, deca- and dodeca-ploids…

Evolutionmedia_common.quotation_subjectZoologychromosome numberPlant ScienceBiologyLycophytaIsoëteGenusPloidyIsoetaceaeBotanyEcology Evolution Behavior and SystematicsHybridmedia_commonEcologySettore BIO/02 - Botanica SistematicaKaryotypebiology.organism_classificationEcology Evolution Behavior and SystematicLycopodiophytaSpeciationTaxonIsoetesSettore BIO/03 - Botanica Ambientale E ApplicataPloidylycophyteKaryology
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