A systematic survey of leaf and stem anatomical characters in the genus Gaultheria and related genera (Ericaceae)

MIDDLETON, D. J., A systematic survey of leaf and stem anatomical characters in the genus Gaultheria and related genera (Ericaceae). Leaf and stem anatomical characters of 123 species within the Gaultheria group of genera of the tribe Andromedeae are surveyed. A number of characters show considerable variation within a species which limits their taxonomic use. Other characters such as marginal sclerenchyma and, to a lesser extent, the hypodermis, the presence of adaxial stomata, the presence of free fibres and the pith type were of more taxonomic interest. These characters are discussed in relation to the generic and infrageneric classification of the group.     

A CRITICAL APPRAISAL OF MODERN GENERIC CONCEPTS IN LICHENOLOGY

After a brief historical survey, some current trends in the delimitation of lichen genera are discussed. A widespread tendency is that of elevating any supposedly monophyletic group of species to genus rank. As the term ‘ monophyletic ’ has no lower limit, this is likely to result in an explosive inflation of new genera, in a severe loss of the information carried by generic names and in a high degree of nomenclatural disorder. Five criteria are proposed for the acceptance or rejection of new generic segregates: (1) DNA testing for monophyly, (2) phylo-genetic analysis, (3) number of characters used, (4) number of species considered, (5) information content of the new splittings. Upon a critical analysis of several recent generic segregations, a more flexible approach to taxonomic ranks is recommended, and particularly, when most of the suggested criteria are not fulfilled, a more frequent use of the subgeneric rank, which does not imply name changes.     

A reappraisal of the family Comasteridae A. H. Clark, 1908 (Echinodermata: Grinoidea), with the description of a new subfamily and a new genus

The family Comasteridae is divided into four subfamilies on the basis of syzygy positions in the division series and proximal arm. Use of this character results in major differences in perceived relationships between genera compared with that obtained when traditional subfamilial characters are used. The primary character previously used to determine comasterid subfamilies, cirrus ornamentation, is rejected as unimportant in recognizing taxa any higher than species. Seventeen genera, including a new genus from the tropical western Atlantic, and 99 species are now recognized in the Comasteridae. Four of these genera and five species cannot be placed within the newly diagnosed subfamilies. Characters of generic importance are considered to be pinnule comb form, mouth position and, to a lesser extent, the characters traditionally used to distinguish genera.     

鲤科鲌亚科鱼类的系统发育及动物地理学

以雅罗鱼亚科为外群,采用分支系统学的原理和方法对鲌亚科17个属(须鳊属除外)进行了系统发育和动物地理学的分析.结果表明,(1)鲌亚科这17个属为一个单系群,并由4个较小的单系群组成;(2)鲌亚科现在的地理分布格局除源自离散事件外,主要源于扩散事件.鲌亚科的特征演化还表明,东亚地区地质历史的反转演化和平行演化可能在鲌亚科系统发育过程中起了重要的作用.     

INDIAN OCEAN NANOPLANKTON. I. RHABDOSPHAERACEAE (PRYMNESIOPHYCEAE) WITH A REVIEW OF EXTANT TAXA1

Family characteristics of the Rhabdosphaeraceae are revised to limit the genera to those having cyrtoliths; genera with placoliths are removed from the family. Rhabdoliths, cyrtoliths bearing a process in the central area, are present in all genera. Coccospheres having monomorphic coccoliths, all being rhabdoliths, form one group within the family, whereas genera with dimorphic coccoliths in the coccosphere comprise a second group. Cyrtoliths without processes in the latter group may be intermixed with rhabdoliths in some genera, whereas other genera have rhabdoliths located only in polar regions of the coccosphere. Two generic nomenclatural changes are proposed, Algirosphaera being the name applied to species previously placed in Anthosphaera, an invalid generic name, and Palusphaera is recognized as a valid monotypic genus, P. vandeli being the name applied to the species that has been named Rhabdosphaera longistylis in recent literature. A new combination is made, Rhabdosphaera xiphos (Deflandre et Fert) comb. nov., recognizing a species formerly known only in sediments as extant. Rhabdosphaera, Acanthoica and Algirosphaera are genera with dimorphic coccoliths in the coccospheres; Discosphaera, Palusphaera and Anacanthoica are genera having monomorphic coccoliths in the coccosphere.     

A SYNOPSIS OF THE GENERA AND SPECIES OF THE TRIBE THELEBOLEAE (= PSEUDOASCOBOLEAE)

Examination of genera of the Pseudoascoboleae (Ascomycetes, Discomycetes, Ascobolaceae) revealed that many were polytypic. Characters presently used to distinguish these genera are considered to be artificial and true relationships cut across accepted generic lines. Of the genera treated, Thecotheus and parts of Ascophanus, since their asci blue in iodine and their spores bear callose-pectic markings, are considered more closely related to the Pezizeae. Other genera are excluded from the Pseudoascoboleae because of other striking characters. Since the Pseudoascoboleae is shown to be an artificial grouping, it is proposed to abandon the name, using instead the tribe name Theleboleae, placed in the Pezizaceae rather than the Ascobolaceae, for all of those genera with asci that do not blue in iodine, with smooth, elliptical spores without oil guttules, and with eight-spored and multispored species. Four new genera are described: Iodophanus, for species of Ascophanus with iodine-positive asci; Coprotus, for segments of Ascophanus and Ryparobius; Caccobius, for species intermediate to Ascozonus and Thelebolus; and Trichobolus, for the setose members of Thelebolus. The species of Ryparobius not belonging to Coprotus are transferred to Thelebolus.     

Comparative study of leaf anatomy of Malaysian species of Chionanthus and Olea (Oleaceae) with special reference to foliar sclereids

The foliar anatomy of 15 Malaysian species of Chionanthus and 3 species of Olea is described and compared with particular reference to sclereids. The anatomy of the two genera is similar except that Chionanthus shows a wider range in sclereid form, eight kinds ofsclereid are recorded. Filiform sclereids are present in all Olea species and most Chionanthus species examined, additional kinds ofsclereid found in these Chionanthus species include astrosclereids, dendrosclereids, osteosclereids and polymorphic sclereids, with brachysclereids of several forms in the petiole. Quantity of sclereids is not related to coriaceousness, which is determined by leaf thickness. Anatomical characters do not support any major grouping of species within Chionanthus and provide further evidence that the sections, Eulinocitra and Ceranthus , are untenable. The distinction between the lepidote scales of Olea and the peltate hairs common to all oleaceous genera is discussed.     

An update to modern taxonomy (2011) of freshwater planktic heterocytous cyanobacteria

It is essential for the modern taxonomic classification of cyanobacteria to be continually updated in accordance with revisions based on molecular sequence comparisons and combined with morphological features, ecophysiological characters and other biochemical and molecular markers (“polyphasic approach”). Several genera, which are characterized by their planktic life form and contain indicator species important for the evaluation of aquatic biocenoses in majority of water bodies are recognized in the monophyletic group of heterocytous cyanobacteria. Current taxonomic revisions (and nomenclatoric consequences) of the specific contents of these heterocytous cyanobacterial generic units are covered by this article. Among these genera, 12 contain only planktic species, three remaining genera contain both planktic and non-planktic species. Comments and suggestions for future research are stressed especially in the ecologically distinct genera, which includes species dominating in the plankton of various reservoir types.     

Review on the use of sexually dimorphic characters in the taxonomy of Diabroticites (Galerucinae,Luperini, Diabroticina)

Sexual dimorphism occurs frequently in Chrysomelidae Latreille, 1802 and is particularly variable in subfamily Galerucinae Latreille, 1802. This diversity has been early noted by authors a potential source of taxonomic characters. The section Diabroticites (Luperini Gistel, 1848) is one of the largest assemblies of chrysomelid genera with currently 823 valid species in 17 genera (12 based on dimorphic characteristics), being most diverse in the neotropical region. Apart from a revision work on the type specimens for the section, there are no general taxonomic studies for this group. The occurrence of sexually dimorphic characteristics in the section Diabroticites is revised and their practical taxonomic relevance evaluated. A total of 240 species was studied (145 species with males available), representing 15 out of the 17 genera included in Diabroticites. The analysis of characters was based on the study of specimens in south-american collections, literature and the aid of photos in online databases. Sexual dimorphism occurred in most species analyzed. Dimorphic features were divided in general (i. e., occur in higher taxa) and special characters (those that support the definition of species and genera). Special dimorphism was observed in every tagma, and most modifications occur in antennae. Characters used as diagnostic of genera often do not correspond to the modifications present in species included in them. Many modifications were considered by earlier authors as a single character, probably due to vague definitions. Most generic definitions are, therefore, inaccurate. The study of morphology and the homology assessment of characters are needed to increase understanding of the genera in Diabroticites.     

Heptageniidae (Insecta,Ephemeroptera) of Thailand

Nine genera and twenty-two species of heptageniid mayflies from Thailand are defined in this present work as well as one suggested further subgenus, Compsoneuria (Siamoneuria) kovaci (species “incertae sedis”) including some particular characters. Taxonomic remarks, diagnoses, line drawings of key characters, distribution, habitat and biological data, and a larval key to the genera and species are provided. The chorionic eggs of eight genera and eight species were observed and shown using a scanning electron microscope.     

Thysanopterans of the generic group Anaphothrips (Thripidae: Thripinae) with emphasis in Central America

A taxonomic revision and phylogenetic analysis of the generic group Anaphothrips are presented. Several genera in Central America are closely related to this generic group. Based on the analysis of characters and its possible evolution, the new genus Nakaharathrips has been segregated from Anaphothrips, and the taxonomic status of the subspecies of Aurantothrips has been changed to the species level. The phylogenetic analysis shows a close relationship between the genera Anaphothrips, Ranjana, Nakaharathrips n.gen., Aurantothrips, Nicolemma n.gen., Ameranathrips, Baileyothrips and Gonzalezya n.gen., where the first lineage is formed by the genera (Ranjana (Aurantothrips+Nicolemma)) and the second lineage contains the genera [(Anaphothrips+Nakaharathrips)(Baileyothrips (Ameranathrips+Gonzalezya)].     

Systematics and phylogeny of the Aglajidae (Opisthobranchia: Mollusca)

The generic limits within the Aglajidae are reviewed and modified, based on the study of 21 species. Navanax Pilsbry, 1895 is reinstated as a genus distinct from Aglaja. The generic placement of several species is altered from previous works. An evaluation of morphological characters suggests that each of six genera has distinctive external morphology. The systematic value of twelve characters is critically reviewed. The evolutionary relationships of the Aglajidae and its genera to other philinacean familes are discussed.     

北京蹄盖蕨科孢子形态的研究Ⅰ. 冷蕨属、羽节蕨属、短肠蕨属

本文利用光学显微镜和扫描电子显微镜对北京产蹄盖蕨科３属４种孢子进行了详细观察,对每个种的形态特征进行了描述。讨论了各属、种间的差异,为蹄盖蕨科系统分类及孢粉学研究提供资料     

Morphology, anatomy and histochemistry of Salicornioideae (Chenopodiaceae) fruits and seeds

BACKGROUND AND AIMS: The subfamily Salicornioideae (Chenopodiaceae) are a taxonomically difficult group largely due to the lack of diagnostic characters available to delineate tribal- and generic-level boundaries; a consequence of their reduced floral and vegetative features. This study examined the variation in fruits and seeds across both tribes of the Salicornioideae to assess if characters support traditional taxonomic sections. METHODS: Light microscopy, environmental scanning electron microscopy and anatomical ultra-thin sectioning were employed to examine variation in fruits and seeds. Sixty-eight representatives across 14 of the 15 genera currently recognized within the tribes Halopeplideae and Salicornieae were examined to determine whether characters support current taxonomic groups. KEY RESULTS: Characters such as seed coat structure, embryo shape, seed orientation, the forms of seed storage proteins and carbohydrates show variation within the Salicornioideae and may be phylogenetically useful. The campylotropous ovule typical of the Chenopodiaceae generally results in a curved embryo; however, many Halosarcia and Sclerostegia species have straight embryos and in Salicornia and Sarcocornia the large peripheral embryo appears bent rather than curved. Seed coat ornamentation of Microcnemum and Arthrocnemum is distinct from other Salicornioideae as the elongated epidermal cells of the exotesta have convex walls. Histochemical stains of anatomical sections of cotyledon cells showed protein bodies were variable in shape, and starch grains were present in some species, namely Salicornia bigelovii, S. europaea and Allenrolfea occidentalis. CONCLUSIONS: While fruits and seeds were found to be variable within the subfamily, no synapomorphic characters support the tribe Halopeplideae as these genera have crustaceous seed coats, curved embryos and abundant perisperm; features characteristic of many of the tribe Salicornieae. The endemic Australian genera are closely related and few seed and fruit characters are diagnostic at the generic level. Nineteen characters identified as being potentially informative will be included in future phylogenetic analyses of the subfamily.     

A cladistic analysis of wax scales (Hemiptera: Coccoidea: Coccidae: Ceroplastinae)

Seven genera of wax scales (Ceroplastinae) have been accepted as valid by some or all coecidologists: Ceroplastes Gray, Ceroplastidia Cockerell, Cerostegia De Lotto, Gascardia Targioni Tozzetti, Paracerostegia Tang, Vinsonia Signoret and Waxiella De Lotto. The status of most these genera is controversial. The present study reviews the taxonomic history of wax scales and presents a new classification based on cladistic analysis of morphological data from the adult females of eighty-three species. The analysis indicates that the wax scales form a monophyletic group, that Waxiella is monophyletic but that Ceroplastidia, Gascardia and Vinsonia are not, and fails to support the generic status of Cerostegia and Paracerostegia. Apart from the type species of Vinsonia , which was placed as a sister to the rest of wax scales, the only other species assigned to Vinsonia and most species of all other genera fall within Ceroplastes in the cladogram. Recognition of any of these genera renders Ceroplastes paraphyletic or polyphyletic. Thus, cladistically, the wax scales should be classified into one genus, Ceroplastes.