scholarly journals Anatomía de la corteza de algunas Gimnospermas

2017 ◽  
pp. 15
Author(s):  
Laura Yáñez-Espinosa ◽  
Teresa Terrazas
Keyword(s):  
Cladistic Analysis ◽  
Structural Diversity ◽  
Secondary Phloem ◽  
Anatomical Features ◽  
Sieve Cells ◽  
Pinus Species ◽  
First Time

The study of bark structural diversity of 17 gymnosperms was performed to describe it macro and microscopically, to elaborate a key and to compare them with den Outer's classification (1967). External bark allows to identify several species in the field. New anatomical features not reported previously were found, e.g. crystals in cellular walls in Araucariaceae and Taxodiaceae, lack of fibers in Cupressus guadalupensis and lignified sieve cells in the collapsed phloem of Pinus species. Ten species, described for the first time, were assigned to one of the types proposed by den Outer. Although the phylogenetic ideas established for the secondary phloem specialization suggested by den Outer have been questioned by the recent studies on fossil gymnosperms and cladistic analysis.

Anatomy and Chemical Composition of Pinus Pinaster Bark

IAWA Journal ◽  
1996 ◽  
Vol 17 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Elsa Nunes ◽  
Teresa Quilhó ◽  
Helena Pereira
Keyword(s):  
Chemical Composition ◽  
Pinus Pinaster ◽  
Variable Number ◽  
Starch Granules ◽  
Secondary Phloem ◽  
Scale Type ◽  
Resin Ducts ◽  
Sieve Cells ◽  
Parenchyma Cells

The secondary phloem of Pinus pinaster Aiton bark has sieve cells and axial and radial parenchyma, but no fibres. Resin ducts are present in fusiform rays . Stiloid crystals, starch granules and tannins occur inside sieve and parenchyma cells. The rhytidome of P. pinaster bark has a variable number of periderms forming scale-type discontinuous layers over expanded parenchyma cells. Phellem comprises 4-6 layers of thickwaIled and little suberized cells and phelloderm a layer of 2 or 3 thickened lignified ceIls and a layer of expanded cells.

The secondary phloem of Austrobaileya scandens

1970 ◽  
Vol 48 (2) ◽  
pp. 341-359 ◽  
Author(s):  
Lalit M. Srivastava
Keyword(s):  
Tannic Acid ◽  
Cross Sections ◽  
Significant Proportion ◽  
Sieve Tube ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Sieve Cells ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Definition Of

The origin of sieve elements and parenchyma cells in the secondary phloem of Austrobaileya was studied by use of serial cross sections stained with tannic acid – ferric chloride and lacmoid. In three important respects, Austrobaileya phloem recalls gymnospermous features: it has sieve cells rather than sieve-tube members; a significant proportion of sieve elements and companion cells arise independently of each other; and sieve areas occur between sieve elements and companion cells ontogenetically unrelated to each other. The angiospermous feature includes origin of most sieve elements and parenchyma, including companion cells, after divisions in phloic initials. In these instances companion cells show a closer ontogenetic relationship to sieve elements than do other parenchyma cells. The combination of gymnospermous and angiospermous features makes phloem of Austrobaileya unique when compared to that of all those species that have been investigated in detail. It is further suggested that the term albuminous cells is inappropriate and should be replaced by companion cells but that the ontogenetic relationship implicit in the definition of companion cells is too restrictive and should be abandoned.

Phylogeny and re-definition of the genus Melanophora (Diptera: Rhinophoridae), with description of a new species from Sardinia

Zootaxa ◽  
2009 ◽  
Vol 2318 (1) ◽  
pp. 552-565 ◽  
Author(s):  
PIERFILIPPO CERRETTI ◽  
THOMAS PAPE
Keyword(s):  
New Species ◽  
Type Species ◽  
Cladistic Analysis ◽  
The Other ◽  
New Combinations ◽  
Generic Delimitation ◽  
Definition Of ◽  
First Time ◽  
A New Species

A cladistic analysis of the genus Melanophora Meigen, 1803 (type-species: Musca grossificationis Linnaeus, 1758 [= Musca roralis Linnaeus, 1758]) is presented and the generic delimitation is critically redefined. The nominal genus-group taxon Bequaertiana Curran, 1929 (type-species: Bequaertiana argyriventris Curran, 1929) is synonymised with Melanophora Meigen syn. nov. The following new combinations are proposed: Melanophora argyriventris (Curran, 1929) comb. nov. and Melanophora basilewskyi (Peris, 1957) comb. nov. Melanophora chia sp. nov. from SW Sardinia is described, illustrated and compared with the other known species of the genus. The male of Melanophora asetosa Kugler, 1978 is described for the first time. Melanophora basilewskyi (Peris, 1957) is recorded from Kenya for the first time.

Phi Thickenings in Fossil Seed Plants from Antarctica

IAWA Journal ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 191-201 ◽  
Author(s):  
Michael A. Millay ◽  
Thomas N. Taylor ◽  
Edith L. Taylor
Keyword(s):  
Middle Triassic ◽  
Cell Layer ◽  
Vascular Cambium ◽  
Secondary Development ◽  
Water Regulation ◽  
Secondary Phloem ◽  
Primary Xylem ◽  
Sieve Cells ◽  
Ray Parenchyma ◽  
Cell Layers

Primary anatomy and secondary development is described for two root types from the Fremouw Peak locality (Transantarctic Mts, Antarctica) of early to middle Triassic age. Roots of Antarcticycas have a bilayered cortex with thick surface cuticle, diarch xylem, and a clearIy defined endodermis surrounded by a single cell layer possessing phi thickenings. Secondary development begins with phellern and phelloderm production from the out er primary phloem position, and is followed bya bifacial vascular cambium next to the primary xylem that pro duces sieve cells and ray parenchyma to the outside. Young roots of Antarcticoxylon are similar to those of Antarcticycas, but may possess 2-3 cell layers with phi thickenings. Secondary development from a bifacial vascular cambium produces alternating bands of sieve cells and phloem parenchyma cells in the secondary phloem and wood with uniseriate rays and scattered axial parenchyma. The presence of phi thickenings and an epidermal cutieie in both roots suggests environmental stress related to water regulation. The occurrence of phi thickenings in the roots of some conifers, angiosperms, a fossil cycad and a probable seed fern suggests this character is of ecological rather than phylogenetic significance.

The genus Hoplothrips in Australia (Thysanoptera, Phlaeothripinae), with eleven new species

Zootaxa ◽  
2020 ◽  
Vol 4718 (3) ◽  
pp. 301-323
Author(s):  
LAURENCE A. MOUND ◽  
JUN WANG ◽  
DESLEY J. TREE
Keyword(s):  
New Species ◽  
Leaf Litter ◽  
Structural Diversity ◽  
First Time

A key to 19 species from Australia in the genus Hoplothrips is provided, including 11 described as new species: H. bellingeni, H. giganteus, H. lamingtoni, H. lihongae, H. lowdeni, H. nelsoni, H. oakeyi, H. reedi, H. tarsus, H. woodsi, H. wrightae. One species, H. semicaecus (Uzel), is recorded in Australia for the first time, and H. corticis (De Geer) and H. orientalis (Ananthakrishnan) are newly recorded from the Australian mainland. Structural diversity among the species of the genus Hoplothrips is discussed. Members of this genus share many character states with species of Deplorothrips, Hoplandrothrips and Psalidothrips that also live as fungal-hyphal feeders on dead branches and in leaf litter. 

Revision of Cyriocosmus Simon, 1903, with notes on the genus Hapalopus Ausserer, 1875 (Araneae: Theraphosidae)

Zootaxa ◽  
2005 ◽  
Vol 846 (1) ◽  
pp. 1 ◽  
Author(s):  
CAROLINE SAYURI FUKUSHIMA ◽  
ROGÉRIO BERTANI ◽  
PEDRO ISMAEL DA SILVA
Keyword(s):  
Cladistic Analysis ◽  
New Combination ◽  
Additional Material ◽  
First Time

The genus Cyriocosmus Simon, 1903 is revised based on most types and additional material from Argentina, Brazil, Colombia, Tobago Island and Venezuela. Two species are newly described from Brazil: Cyriocosmus nogueira-netoi and Cyriocosmus fernandoi. The species Cyriocosmus fasciatus (Mello-Leitão, 1930), formerly synonymized with Cyriocosmus elegans, is revalidated. Metriopelma nigriventris (Mello-Leitão, 1939) and Cyriocosmus butantan Pérez-Miles, 1998 are transferred to Hapalopus Ausserer, 1875, proposing Hapalopus nigriventris (Mello-Leitão, 1939) new combination and Hapalopus butantan (Pérez-Miles, 1998) new combination. The female of Hapalopus butantan is described for the first time. All 11 species of Cyriocosmus are diagnosed and keyed. A cladistic analysis with 28 characters and 19 taxa was carried out. Searches using three phylogenetic packages found a single, totally resolved tree with the same topology.

scholarly journals Acherontiscus caledoniae : the earliest heterodont and durophagous tetrapod

2019 ◽  
Vol 6 (5) ◽  
pp. 182087 ◽  
Author(s):  
Jennifer A. Clack ◽  
Marcello Ruta ◽  
Andrew R. Milner ◽  
John E. A. Marshall ◽  
Timothy R. Smithson ◽  
...  
Keyword(s):  
Vertebral Column ◽  
Cladistic Analysis ◽  
Early Carboniferous ◽  
Late Devonian ◽  
Dental Morphology ◽  
Hard Tissue ◽  
Skull Length ◽  
Varied Diet ◽  
First Time ◽  
Morphological Innovation

The enigmatic tetrapod Acherontiscus caledoniae from the Pendleian stage of the Early Carboniferous shows heterodontous and durophagous teeth, representing the earliest known examples of significant adaptations in tetrapod dental morphology. Tetrapods of the Late Devonian and Early Carboniferous (Mississippian), now known in some depth, are generally conservative in their dentition and body morphologies. Their teeth are simple and uniform, being cone-like and sometimes recurved at the tip. Modifications such as keels occur for the first time in Early Carboniferous Tournaisian tetrapods. Acherontiscus , dated as from the Pendleian stage, is notable for being very small with a skull length of about 15 mm, having an elongate vertebral column and being limbless. Cladistic analysis places it close to the Early Carboniferous adelospondyls, aïstopods and colosteids and supports the hypothesis of ‘lepospondyl’ polyphyly. Heterodonty is associated with a varied diet in tetrapods, while durophagy suggests a diet that includes hard tissue such as chitin or shells. The mid-Carboniferous saw a significant increase in morphological innovation among tetrapods, with an expanded diversity of body forms, skull shapes and dentitions appearing for the first time.

scholarly journals Double the Chemistry, Double the Fun: Structural Diversity and Biological Activity of Marine-Derived Diketopiperazine Dimers

Marine Drugs ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. 551 ◽  
Author(s):  
Nelson G. M. Gomes ◽  
Renato B. Pereira ◽  
Paula B. Andrade ◽  
Patrícia Valentão
Keyword(s):  
Wide Spectrum ◽  
Structural Diversity ◽  
Pharmacological Properties ◽  
Binding Ability ◽  
Recognition Sites ◽  
Naturally Occurring ◽  
Bioactive Properties ◽  
Models Of Disease ◽  
First Time ◽  
Biosynthetic Machinery

While several marine natural products bearing the 2,5-diketopiperazine ring have been reported to date, the unique chemistry of dimeric frameworks appears to remain neglected. Frequently reported from marine-derived strains of fungi, many naturally occurring diketopiperazine dimers have been shown to display a wide spectrum of pharmacological properties, particularly within the field of cancer and antimicrobial therapy. While their structures illustrate the unmatched power of marine biosynthetic machinery, often exhibiting unsymmetrical connections with rare linkage frameworks, enhanced binding ability to a variety of pharmacologically relevant receptors has been also witnessed. The existence of a bifunctional linker to anchor two substrates, resulting in a higher concentration of pharmacophores in proximity to recognition sites of several receptors involved in human diseases, portrays this group of metabolites as privileged lead structures for advanced pre-clinical and clinical studies. Despite the structural novelty of various marine diketopiperazine dimers and their relevant bioactive properties in several models of disease, to our knowledge, this attractive subclass of compounds is reviewed here for the first time.

Wood anatomy of the neotropical liana lineage Paullinia L. (Sapindaceae)

IAWA Journal ◽  
2020 ◽  
Vol 41 (3) ◽  
pp. 278-300
Author(s):  
Joyce G. Chery ◽  
Israel L. da Cunha Neto ◽  
Marcelo R. Pace ◽  
Pedro Acevedo-Rodríguez ◽  
Chelsea D. Specht ◽  
...  
Keyword(s):  
Wood Anatomy ◽  
Functional Anatomy ◽  
Anatomical Study ◽  
Secondary Phloem ◽  
Phylogenetic Constraint ◽  
Axial Parenchyma ◽  
Anatomical Features ◽  
Ray Parenchyma ◽  
Functional Implications ◽  
Cambial Variants

Abstract The liana genus Paullinia L. is one of the most speciose in the neotropics and is unusual in its diversity of stem macromorphologies and cambial conformations. These so-called “vascular cambial variants” are morphologically disparate, evolutionarily labile, and are implicated in injury repair and flexibility. In this study, we explore at the finer scale how wood anatomy translates into functions related to the climbing habit. We present the wood anatomy of Paullinia and discuss the functional implications of key anatomical features. Wood anatomy characters were surveyed for 21 Paullinia species through detailed anatomical study. Paullinia woods have dimorphic vessels, rays of two size classes, and both septate and non-septate fibers. Fibriform vessels, fusiform axial parenchyma, and elements morphologically intermediate between fibers and axial parenchyma were observed. Prismatic crystals are common in the axial and/or ray parenchyma, and laticifers are present in the cortex and/or the early-formed secondary phloem. Some features appear as unique to Paullinia or the Sapindaceae, such as the paucity of axial parenchyma and the abundance of starch storing fibers. Although many features are conserved across the genus, the Paullinia wood anatomy converges on several features of the liana-specific functional anatomy expressed across distantly related lianas, demonstrating an example of convergent evolution. Hence, the conservation of wood anatomy in Paullinia suggests a combination of phylogenetic constraint as a member of Sapindaceae and functional constraint from the liana habit.

scholarly journals BARK ANATOMY OF LATE PERMIAN GLOSSOPTERID TREES FROM ANTARCTICA

IAWA Journal ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 444-458 ◽  
Author(s):  
Anne-Laure Decombeix ◽  
Edith L. Taylor ◽  
Thomas N. Taylor
Keyword(s):  
Late Permian ◽  
Secondary Phloem ◽  
Outer Bark ◽  
Thin Sections ◽  
Wide Range ◽  
The Matrix ◽  
Bark Tissue ◽  
Bark Anatomy ◽  
Extinct Group ◽  
First Time

The Glossopteridales are an extinct group of seed plants that dominated Gondwanan floras during the Permian. Their remains are found across a wide range of habitats and paleolatitudes, and it is particularly interesting to understand the anatomical characteristics that might have enabled such an extensive distribution. Here, we document for the first time the bark anatomy of high-latitude glossopteridalean trees using peels and thin sections made from a Late Permian trunk from Skaar Ridge, Antarctica. The bark is 3 cm thick. The secondary phloem is composed of sieve cells, axial and ray parenchyma, and fibers arranged in discontinuous unicellular tangential layers. The outer bark is a rhytidome, with numerous alternating layers of periderm and non-conducting secondary phloem showing some proliferation of the axial parenchyma. Successive periderms mostly run parallel to the cambium, with some longitudinal undulation and rare connections between two periderms. A similar anatomy was observed in bark fragments found isolated in the matrix or closely associated with large glossopterid stems or roots. The anatomy of the Skaar Ridge specimens shows that Antarctic Glossopteridales had a relatively thick, probably stringy bark. The retention of a significant amount of insulating dead bark tissue on the trunk likely provided protection of the cambium, conducting secondary phloem, and potential latent buds against biotic and abiotic environmental hazards (fire, frost, scalding, insects, etc.) and may have contributed to the extensive paleolatitudinal distribution of the Glossopteridales during the Permian.

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