Search results for "Taxonomy"
showing 10 items of 1229 documents
A Nomenclatural and Taxonomic Revision of the Senecio squalidus Group (Asteraceae)
2022
Senecio squalidus (Asteraceae) currently includes nine subspecies distributed in North and Central Europe and in the Mediterranean basin. Within this taxonomic aggregate, many species have been described, but research on their nomenclatural types is incomplete. A complete nomenclatural survey of 19 names belonging to this taxonomically critical group was carried out. Fourteen lectotypes are here designated. The nomenclatural analysis, complemented by field investigations in the type localities of the taxa described in the Central Mediterranean, allowed us to accept 10 species. Accordingly, we proposed here a new name and a new missing combination at a specific level: S. aknoulensis and S. c…
Secondary Education Students’ Questions on Experimental Devices
2012
Las preguntas forman parte esencial del trabajo que desarrollan los científicos para construir nuevo conocimiento. Sin embargo, los alumnos formulan un número muy escaso de preguntas en las situaciones usuales de aula. En este trabajo se realiza una revisión de las investigaciones realizadas sobre génesis de preguntas y se describen tres estudios empíricos realizados con estudiantes de diferentes niveles educativos ante dispositivos experimentales. Los objetivos fueron: 1) Estimular y analizar las preguntas de los estudiantes cuando intentan comprender los dispositivos; 2) Contrastar la idea de que la mayoría de preguntas destinadas a obtener información tienen su origen en inferencias fall…
Observaciones sobre algunos caracteres de valor taxonómico en el grupo de los carófitos
1990
The variability of the microstructurals characters and mineralogical composition of the oogonia of some charophytes extant and fossils is described. Two types of microstructures (W & V) are find. These are conservative into populations and are not able to change by the environmental factors. Moreover, these structures are quite constant in some of the phylogenetics groups studied. Consequently it is proposed its utilization in taxonomy. The apparition of original compounds in the Charophyta (vaterite. whewelite, aragonite, etc.) is important because it supports an old idea that considerates the Charophyta as an autonomous class between the Clorophyta and the Traqueophyta.<br><b…
A Synopsis of the Genus Stipa (Poaceae) in Middle Asia, Including a Key to Species Identification, an Annotated Checklist, and Phytogeographic Analys…
2020
The genus Stipa L. comprises over 150 species, all native to the Old World, where they grow in warm temperate regions throughout Europe, Asia, and North Africa. It is one of the largest genera in the family Poaceae in Middle Asia, where one of its diversity hotspots is located. However, identification of Middle Asian Stipa species is difficult because of the lack of new, comprehensive taxonomic studies including all of the species recorded in the region. We present a critical review of the Mid-Asian representatives of Stipa, together with an identification key and taxonomic listing. We relied on both published and unpublished information for the taxa involved, many of which are poorly known…
Lycopodiidae for the “Flora Critica d’Italia”: material and methods
2015
Procedures are presented that were followed during the preparation of the first pteridophyte family treatments for the “Flora Critica d’Italia”: Lycopodiaceae, Isoetaceae, Selaginellaceae. The work was mainly based on the study of literature and herbarium specimens. In some cases SEM observation of spores has proved useful. Data collected from herbarium specimens and other verified sources were loaded into a database, from which a distribution map was prepared for each taxon. Several preliminary papers have been published, and for each family a taxonomic conspectus, with type designations, maps and an identification key, has been prepared. The treatment of these three families for the “Flor…
Quill mites (Acari: Syringophilidae) from Aegithalos caudatus (Passeriformes: Aegithalidae)
2004
Three species of syringophilid mites (Acari: Syringophilidae) were collected from quills of Aegithalos caudatus (Passeriformes: Aegithalidae) in Poland, Picobia caudati sp. n. from body feathers, Dissonus scirpaceus Skoracki, 1999 from rectrices, and Syringophilopsis aegithali Bochkov et al., 2001 from secondaries.
ITS1 region of the nuclear ribosomal DNA of the mycoparasite Pythium periplocum, its taxonomy, and its comparison with related species.
2000
Pythium periplocum Drechsler was isolated from some soil samples taken in the botanical garden of Tenerife, Canary Islands. This fungus has been found to be an aggressive mycoparasite of Botrytis cinerea. It is unique amongst the members of the genus Pythium because of the character combination of inflated filamentous type of sporangia and ornamented oogonia. The taxonomic description of this fungus and its comparison with related species, together with the polymerase chain reaction of the internal transcribed spacer of its nuclear ribosomal DNA, are discussed in this article.
Coxal combs in the Cydnidae sensu lato and three other related “cydnoid” families – Parastrachiidae, Thaumastellidae, Thyreocoridae (Hemiptera: Heter…
2010
Lis, Jerzy A. (2010): Coxal combs in the Cydnidae sensu lato and three other related " cydnoid " families - Parastrachiidae, Thaumastellidae, Thyreocoridae (Hemiptera: Heteroptera): functional, taxonomic, and phylogenetic significance. Zootaxa 2476: 53-64, DOI: 10.5281/zenodo.893992
<p><strong><em>Linaria semialata</em> and <em>L. amethystea </em>subsp.<em> aedoi</em>,<em> <…
2020
Two new taxa of the genus Linaria are described, illustrated and compared, through a morphometric analysis, to morphologically similar species from L. sect. Supinae: L. amethystea, L. diffusa, L. intricata, and L. orbensis. A Principal Component Analysis and Linear Discriminant Analysis were carried out in order to find out which morphological characters were the most important to discriminate these species. Morphometric analyses revealed that discrimination of species were more related to their particular morphological character combinations than to a private character. Two taxa are described as new to science, by providing a detailed description, illustrations, scanning-electron micrograp…
Classification of tall-forb vegetation in the Pamir-Alai and western Tian Shan Mountains (Tajikistan and Kyrgyzstan, Middle Asia)
2020
Aims: To complete the syntaxonomic scheme for tall-forb vegetation of the montane and alpine belts in the Pamir-Alai and western Tian Shan Mountains in Tajikistan and Kyrgyzstan with some remarks on its environmental predictors. Study area: Middle Asia: Tajikistan and Kyrgyzstan. Methods: A total of 244 relevés were sampled in 2013–2019 using the seven-degree cover-abundance scale of the Braun-Blanquet approach. These were classified with a modified TWINSPAN algorithm with pseudospecies cut-levels 0%, 5% and 25%, and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. NMDS was used to explore the relationsh…