Systematic implications of achene micromorphology in Carex section Hymenochlaenae (Cyperaceae)

1990 ◽  
Vol 68 (3) ◽  
pp. 630-639 ◽  
Author(s):  
Marcia J. Waterway
Keyword(s):  
Epidermal Cells ◽  
Evolutionary Relationships ◽  
Character State ◽  
Primitive Character ◽  
Modified Silica ◽  
Surface Features ◽  
Parallel Development ◽  
Wall Structures ◽  
Epidermal Features

The structures of the achene epidermal cells and their included silica deposits are illustrated and described for 28 species that have been referred to Carex section Hymenochlaenae. On the basis of these epidermal features, there are anomalous species in nearly all of the subsections and sections that have been circumscribed by Kükenthal, Mackenzie, Ohwi, and Koyama. Furthermore, some species with nearly indistinguishable achene surface features have quite different overall morphologies and have traditionally been placed in different sections. Similarities in the structure of the silica deposits in the achene epidermal cells may result from the retention of the primitive character state in several different lineages or from parallel development of modified silica bodies or wall structures in different lineages. Levels of homoplasy appear to be too high to make these characters reliable indicators of evolutionary relationships in Carex section Hymenochlaenae.

The epidermis in Passerina/ (Thymelaeaceae): structure, function and taxonomic significance

Bothalia ◽  
2000 ◽  
Vol 30 (1) ◽  
pp. 69-86 ◽  
Author(s):  
C. L. Bredenkamp ◽  
A. E. Van Wyk
Keyword(s):  
Cell Walls ◽  
Mediterranean Climate ◽  
High Light Intensity ◽  
Epidermal Cells ◽  
Cell Orientation ◽  
Abaxial Surface ◽  
Epidermal Structure ◽  
Interspecific Differences ◽  
Epidermal Features ◽  
Structural Adaptations

Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.

scholarly journals Cambrian stem-group annelids and a metameric origin of the annelid head

2015 ◽  
Vol 11 (10) ◽  
pp. 20150763 ◽  
Author(s):  
Luke Parry ◽  
Jakob Vinther ◽  
Gregory D. Edgecombe
Keyword(s):  
Anterior Segment ◽  
Character State ◽  
Early Cambrian ◽  
Primitive Character ◽  
Burgess Shale ◽  
Crown Group ◽  
Middle Cambrian ◽  
Stem Group

The oldest fossil annelids come from the Early Cambrian Sirius Passet and Guanshan biotas and Middle Cambrian Burgess Shale. While these are among the best preserved polychaete fossils, their relationship to living taxa is contentious, having been interpreted either as members of extant clades or as a grade outside the crown group. New morphological observations from five Cambrian species include the oldest polychaete with head appendages, a new specimen of Pygocirrus from Sirius Passet, and an undescribed form from the Burgess Shale. We propose that the palps of Canadia are on an anterior segment bearing neuropodia and that the head of Phragmochaeta is formed of a segment bearing biramous parapodia and chaetae. The unusual anatomy of these taxa suggests that the head is not differentiated into a prostomium and peristomium, that palps are derived from a modified parapodium and that the annelid head was originally a parapodium-bearing segment. Canadia , Phragmochaeta and the Marble Canyon annelid share the presence of protective notochaetae, interpreted as a primitive character state subsequently lost in Pygocirrus and Burgessochaeta , in which the head is clearly differentiated from the trunk.

scholarly journals Foliar epidermal characters and petiole anatomy of four species of Citrus L. (Rutaceae) in South-western Nigeria

2012 ◽  
Vol 19 (1) ◽  
pp. 25-31 ◽  
Author(s):  
C.S. Ogundare ◽  
S.A. Saheed
Keyword(s):  
Epidermal Cells ◽  
Secretory Cavity ◽  
Abaxial Surface ◽  
Adaxial Surface ◽  
Close Relationship ◽  
Plant Taxon ◽  
Anatomical Characters ◽  
Polygonal Shape ◽  
Epidermal Features

Studies on the leaf epidermal characters and petiole anatomy of four species of Citrus L. viz., C. limon (L.) Burm., C. paradisi Macf., C. reticulata Blanco and C. sinensis (L.) Osbeck were carried out to establish and document their foliar anatomical characters with the aim of separating them from the modified varieties been cultivated globally. Leaf epidermal features that revealed close relationship among these taxa include hypostomatic condition, stomata shape and type, presence of secretory cavity on the adaxial surface, and polygonal shape of epidermal cells. The absence of secretory cavity on the abaxial surface separates C. limon and C. sinensis from others. Petiole anatomy revealed that the outline is flat without ribs in C. sinensis, convex with short ribs in C. reticulata, convex with long ribs in C. paradisi while in C. limon it is circular without ribs. Presence of trichomes and crystals distinguishes C. paradisi from the rest.DOI: http://dx.doi.org/10.3329/bjpt.v19i1.10938Bangladesh J. Plant Taxon. 19(1): 25-31, 2012 (June)

The oldest microsaur (Amphibia)

1991 ◽  
Vol 65 (2) ◽  
pp. 314-322 ◽  
Author(s):  
Robert L. Carroll ◽  
Paul Bybee ◽  
William D. Tidwell
Keyword(s):  
North American ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Character State ◽  
Primitive Character ◽  
Fossil Plants ◽  
Shale Formation ◽  
Paleozoic Tetrapods

Utaherpeton franklini n. gen. and sp., from the Manning Canyon Shale Formation of Utah, is the oldest known microsaur. The horizon is dated as equivalent to the lowermost Namurian B of Europe (transitional from Upper Mississippian into lowermost Pennsylvanian in North American terminology) on the basis of a rich assemblage of fossil plants. The specimen may be tentatively placed within the suborder Microbrachomorpha. It exhibits the primitive character state for many microsaur features, but no synapomorphies are recognized that support a specific sister-group relationship between microsaurs and any other group of Paleozoic tetrapods.

scholarly journals Leaf surface of two understorey shrubs Rudgea Decipiens Müll. Arg. and Rudgea macrophylla Benth. (Rubiaceae)

Rodriguésia ◽  
1993 ◽  
Vol 45-49 (71-75) ◽  
pp. 7-13 ◽  
Author(s):  
André Mantovani ◽  
Ricardo Cardoso Vieira
Keyword(s):  
Environmental Factors ◽  
Atlantic Forest ◽  
Leaf Surface ◽  
Epidermal Cells ◽  
Surface Features ◽  
Unusual Pattern ◽  
Abaxial Leaf Surface ◽  
Surface Correlations

ABSTRACT MICROMORPHOLOGICAL CHARACTERISTICS OF LEAF SURFACE OF TWO SPECIES OF RUDGEA ARE PRESENTED. THE STUDY WAS BASED ON MATERIAL FROM THE UNDERSTOREY OF ATLANTIC FOREST. SPECIAL ATTENTION IS PAID TO THE OCCURENCE OF SMOOTH AND STRIATED CUTICLE, TO PARACYTIC STOMATA,(SOME OF WHICH EXIHBIT AN UNUSUAL PATTERN IN THE ARRANGEMENT OF THE SURROUNDING EPIDERMAL CELLS) AND TO PAPILLAE, WHICH ARE IRREGULARLY DISTRIBUTED ON THE ABAXIAL LEAF SURFACE. CORRELATIONS BETWEEN THE LEAF SURFACE FEATURES AND ENVIRONMENTAL FACTORS ARE DISCUSSED.

A new specimen of Utatsusaurus (Reptilia: Ichthyosauria) from the Lower Triassic Sulphur Mountain Formation of British Columbia

1993 ◽  
Vol 30 (3) ◽  
pp. 486-490 ◽  
Author(s):  
Elizabeth L. Nicholls ◽  
Donald Brinkman
Keyword(s):  
British Columbia ◽  
Lower Triassic ◽  
Geographic Range ◽  
Character State ◽  
Primitive Character

An incomplete skull and mandible of the primitive ichthyosaur Utatsusaurus is described from the Lower Triassic Vega Phroso Member of the Sulphur Mountain Formation of British Columbia. The specimen contributes to our knowledge of the cranial anatomy of the genus, which was previously known primarily from postcranial material, and extends its geographic range to Canada. The presence of an isodont dentition in this primitive genus suggests that isodonty rather than heterodonty may be the primitive character state for the Ichthyosauria.

Anatomical aspects of the taxonomy of sedges (Carex, Cyperaceae)

1990 ◽  
Vol 68 (7) ◽  
pp. 1449-1456 ◽  
Author(s):  
L. A. Standley
Keyword(s):  
Cluster Algorithm ◽  
Single Layer ◽  
Epidermal Cells ◽  
Primitive Character ◽  
Bulliform Cells ◽  
Group Criterion ◽  
Phylogenetic Studies ◽  
As Species ◽  
Anatomical Characters ◽  
The Common

Patterns of variation in the anatomy of achene epidermis and leaves were examined to assess the utility of anatomical characters in systematic and phylogenetic studies of Carex and the Cyperaceae. This study was based primarily on a review of the available literature. In addition, foliar anatomy of species in Carex sect. Phacocystis was investigated and patterns of variation within the section were analyzed using a centroid cluster algorithm. Nearly all genera and all sections of Carex for which data are available include species with single conical silica bodies in the achene epidermal cells as well as species with more elaborate, presumably derived, silica bodies. Similarly, most sections within Carex include species that have hypostomatous leaves with a single layer of bulliform cells and that lack papillae, as well as species with amphistomatous leaves, papillose epidermal cells, or multiple bulliform cells. Application of the "common equals primitive" in group criterion for determining evolutionary polarity indicates that single conical silica bodies and epapillose hypostomatous leaves are primitive character states in Carex. As both primitive and derived character states are widely distributed among sections, anatomical characters should not be generally applied as measures of similarity in phenetic approaches to classification but have potentially major importance in phylogenetic studies within and among sections.

An Examination of the Relationships Between Extant Dolomena Wenz, 1940, Doxander Wenz, 1940, Mirabilistrombus Kronenberg, 1998, Neodilatilabrum Dekkers, 2008 and Labiostrombus Oostingh, 1925 (Stromboidea: Neostromboidae: Strombidae)

The Festivus ◽  
2020 ◽  
Vol 52 (1) ◽  
pp. 39-59
Author(s):  
Aart Dekkers ◽  
Stephen Maxwell
Keyword(s):  
Maximum Parsimony ◽  
Evolutionary Relationships ◽  
Character State ◽  
State Analysis

This paper presents an examination of the relationships between Dolomena, Doxander, Mirabilistrombus, Neodilatilabrum and Labiostrombus using character state analysis and maximum parsimony. Hypothesized relationships are presented through the introduction of definitions that bridge the understanding of the evolutionary relationships with the applied nomenclature. Dolomenini is introduced to incorporate two new subtribes: Dolomenina which combines parts of Dolomena ex Abbott (1960) and Labiostrombus; and Doxanderina, which encloses Doxander and Neodilatilabrum. Based on the generated phylogeny, Amabiliplicatus, Pacificus and Dominus are introduced, while Ministrombus is validated as monophyletic. The clustering of Neodilatilabrum and Doxander within Doxanderina, and the nesting of Labiostrombus within the Dolomenini are major revisions to Stromboid systematics.

Foliar anatomy of the subfamily Myrtoideae (Myrtaceae)

2009 ◽  
Vol 57 (2) ◽  
pp. 148 ◽  
Author(s):  
C. M. V. Cardoso ◽  
S. L. Proença ◽  
M. G. Sajo
Keyword(s):  
Vascular Bundle ◽  
Vascular System ◽  
Diagnostic Value ◽  
Bundle Sheath ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Palisade Parenchyma ◽  
Surface Features ◽  
Foliar Anatomy ◽  
Secretory Cavities

The foliar structure of 44 species of Myrtoideae Nied. (Myrtaceae) was described to characterise the anatomy of the leaves in this subfamily and also to recognise particular features in each genus and/or subtribe. In the present study, nine genera of the subtribe Myrtinae, five genera of the subtribe Myrciinae and eight genera of the subtribe Eugeniinae were examined. All of them have dorsiventral and hypostomatic leaves, with stomata slightly protruded in relation to other epidermal cells; the leaves also present secretory cavities, idioblasts containing druses and vascular bundles with phloem on both adaxial and abaxial sides. Some surface features have diagnostic value for all genera of these three subtribes, such as the percentage of palisade parenchyma, the presence or absence of an adaxial hypodermis, the occurrence of an extension to the vascular bundle sheath, and the shape and position of the vascular system of the midrib. These features are described for each of the species studied and the results are discussed in a taxonomical context.

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