Search results for "Isoete"

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.

A contribution to the phylogeny and biogeography of the genus Isoetes (Isoetaceae, Lycopodiidae) in the Mediterranean region

2019

To better understand the phylogeny of Isoetes species in the Mediterranean region, sequences of the second intron of a LFY-like homolog were determined for six populations of three Mediterranean Isoetes species and analyzed with other LFY and ITS sequences of Euro-Mediterranean species available in GenBank. Nomenclature of selected species was updated according to recent literature. Investigations of voucher specimens from previously sequenced taxa revealed that a specimen of I. histrix from Crete, Greece used in several previous molecular studies is probably I. phrygia. Analysis of the limited LFY and ITS DNA sequence data presented here agrees with the organization of Mediterranean specie…

Isoëtes todaroana (Isoëtaceae, Lycopodiophyta), a New Species from Sicily (Italy)

2009

Isoetes todaroana, a new species from western Sicily (Italy), is described. Morpholog- ical, anatomical and ecological characters are given. The main differential characters are the presence of only two leaf air chambers, rather than four as in all other known species of the genus, and the shape of the scales, which have two lateral rounded lobes and one central spine-like lobe, together with its peculiar calcophilic habitat. So far, the species is known from a single locality.

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…

Contributo alla Flora Critica d'Italia: le specie del genere Isoetes

2013

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…

An updated catalogue of chromosome numbers in the genus Isoetes L. (Isoetaceae, Lycopodiophyta)

2010

Approccio micromorfologico alla sistematica del genere Isoëtes (Isoëtaceae, Lycopodiophyta): analisi della superficie delle megaspore

2011

Clarifying the nomenclature of some Euro-Mediterranean quillworts ( Isoetes , Isoetaceae): Indicator species and species of conservation concern

2018

International audience; To stabilize the application of some names in the genus Isoetes in the Mediterranean biodiversity hotspot, we studied herbarium specimens and imaged spores with scanning electron microscopy, with special reference to those taxa in the I. lon‐gissima and I. histrix groups that were described from France, Algeria and Turkey, and are in need of a taxonomic revision. The following names are lectotypified: I. adspersa, I. boryana, I. delalandei, and I. viollaei. Holotypes of I. perralderiana and I. olympica were ascertained. We conclude that I. boryana (listed in the “Bern Convention” and in the European Union “Habitats” Directive) justifies consideration at species rank,…

Disentangling Isoetes setacea and removing threats to Isoetes echinospora

2015

The name Isoetes setacea has been applied to two different species, causing nomenclatural and taxonomic confusion. Some authors have rejected it on that account, yet it is currently used in a sense that is incompatible with its type. That type represents one of two similar species, I. echinospora and I. lacustris, which still today grow together at the type locality. An epitype is designated here, ensuring that I. setacea is sunk in synonymy under I. lacustris. A second name potentially threatening I. echinospora is I. tenella. It is currently regarded as a synonym of I. lacustris, but its type, a plate in Flora Danica, cannot be confidently identified, nor are there any specimens associate…