Time filter

Source Type

Rolleri C.H.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves | Martinez O.G.,National University of Salta | Prada C.,Complutense University of Madrid
Botanica Complutensis | Year: 2010

Huperzia reflexa and Lycopodiella cernua are recorded for the first time for the northwest of Argentina; along with the new records, the characters of the leaf morphology and spores are analyzed, and updated descriptions and geographical distribution of both taxa are also given. Three of the four genera of the Lycopodiaceae are present so far in the area: Huperzia, Lycopodium and Lycopodiella, and the number of species come to nine. To facilitate the recognition of all taxa, this paper also includes a key for their determination. Source

Gonzalez G.E.,University of Buenos Aires | Prada C.,Complutense University of Madrid | Rolleri C.H.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves
Gayana - Botanica | Year: 2010

A new chromosome count on Blechnum hastatum, together with the study of the ontogeny and development of the leptosporangia of this taxon, and of B. occidentale is carried out here. Adult leptosporangia of other taxa of the genus Blechnum, such as those of B. australe subsp. auriculatum, B. glandulosum and B. mochaenum subsp. mochaenum are also compared. In relation with the cytology of B. hastatum, 33 bivalents at diakinesis were counted, indicating that it is a diploid with a chromosome number 2n=66, which coincides with a previous count, and also places the taxon in the sequence of basic chromosome numbers known for the genus, ie x=33, which seems to be the most frequent. The ontogeny of the leptosporangia was studied for the first time in B. hastatum and B. occidentale. The sporangia initiate from a single initial epidermal cell, which may belong to the commissural area or to the indusia; they develop a long pedicel with three rows of long or short cells, short cells being the most common condition found in B. hastatum, while long cells were seen in B. occidentale. The pedicels are at their maximum length before the capsule ripens. The stomium usually bears no more than 6-8 cells in all species, with a labiate aperture. The capsules have an indurated vertical annulus, that reach the base of the capsule, and have up to 14 cells in B. australe subsp. auriculatum and B. glandulosum, up to 18 in B. hastatum and up to 21 in B. mochaenum subsp. mochaenum and B. occidentale; the number of indurate cells may be a new useful diagnostic trait in the genus. Source

Gabriel Y Galan J.M.,Complutense University of Madrid | Prada C.,Complutense University of Madrid | Rolleri C.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves | Ainouche A.,French National Center for Scientific Research | Vicent M.,Complutense University of Madrid
Turkish Journal of Botany | Year: 2013

Blechnaceae is an important leptosporangiate family (9-10 genera, about 250 species). It is monophyletic and distributed mainly in tropical America and Australasia. Among the species 80% belong to Blechnum, a genus with a very complex taxonomy and uncertain internal relationships. In terms of American diversity, the results of morphological studies have arrived at 8 informal groups. Molecular works on this genus are scarce, and there is no information for the majority of American species. The main objective of this work was to evaluate whether the groups proposed to organise the diversity of American of Blechnum are consistent with a molecular analysis. We sequenced 2 chloroplastic regions from species representing all of the groups. In our molecular analysis most of the informal groups were maintained as well supported clades. Only 2 species, B. brasiliense and B. spicant, appear to be isolated from their alleged relatives. Combining our molecular results with previous morphological knowledge, we propose the recognition of 4 lineages: 1) B. serrulatum, 2) B. spicant, and 3) core Blechnum, which represents a large clade that can be divided into core Blechnum I (arborescent species, cordatoids, and B. brasiliense) and core Blechnum II (epiphytic species and herbaceous terrestrials, both monomorphic and dimorphic groups). © TÜBİTAK. Source

Baran E.J.,National University of La Plata | Rolleri C.H.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves
Revista Brasileira de Botanica | Year: 2010

Frond samples of the eusporangiate ferns Marattiaceae genera Angiopteris, Christensenia, Danaea and Marattia were investigated by infrared spectroscopy, under different experimental conditions. The results confirmed the previously reported accumulation of biogenic silica (SiO2) in tissues of these ferns and also showed, for the first time, the presence of calcium oxalate in this group of plants, probably as weddellite. The ability to biomineralize SiO2, to produce and accumulate biogenic silica, is suggested now to be a general family trait of the Marattiaceae. Source

Dedomenici A.C.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves | Leveratto D.,National University of La Plata | Ringuelet J.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves | Passarelli L.,Laboratorio Of Estudios Of Anatomia Vegetal Evolutiva Y Sistematica Leaves
Botanica Complutensis | Year: 2011

A study of the pollen present in honey from an apiary located in the area of the Depresion del Salado, Buenos Aires, Argentina, in order to observe the plants used by Apis meilifera L. in an environment that has been affected by periodic floods that changed the vegetation, and making comparisons with existing data. Thirty one pollen types belonging to fifteen botanical families were identified. All samples were monofloral of Lotus tenuis with high percentages, above 50%. The results show significant variation respect to previous data on resources used by the honeybee in this area. It makes a new contribution to knowledge of the floral origin of honey from the region that will affect their commercial value. Source

Discover hidden collaborations