Showing papers on "Genus published in 1996"

A synopsis of Ipomoea (Convolvulaceae) in the Americas

Abstract: The genus Ipomoea comprises the largest number of species within the Convolvulaceae. Throughout the world Ipomoea is usually estimated to contain c. 500 species (e.g., Mabberley, 1989; McDonald & Mabry, 1992). After our compilation, we believe Ipomoea is more likely to contain 600-700 species. Over half of them are concentrated in the Americas, where the total may approach 500 taxa, mostly native and a few introduced. Although there are recent publications dealing with Ipomoea in the floras of several American countries (O'Donell, 1941-1960b; Austin, 19751991b; Austin & Cavalcante, 1982; Austin & al., 1986; McDonald, unpubl. thesis 1978, unpubl. diss. 1982, 1982-1995; McDonald & Austin, 1990; McDonald & Mabry, 1992; Wilkin, 1995), there is no single reference summarizing all the species currently recognized in the western hemisphere. The purpose of this publication is to make available an updated list with relationships of American Ipomoea species examined thus far. There certainly are more species in the Americas than recognized here, especially in Brazil, Bolivia and Paraguay, but many of these have not been studied since Meisner (1869). Moreover, there are species remaining undescribed and/or undiscovered. Infrageneric placement is given, where known, and a documented American geographical range is provided for each species.

Four new genera based on Achnanthes (Achnanthidium) together with a re-definition of Achnanthidium

Abstract: The genus Achnanthidium comprises a collection of monoraphid species common in freshwaters and less so in marine habitats, though the latter are relatively uninvestigated as far as this genus is concerned. We propose that Achnanthidium be confined to the taxa around A. minutissima. Some of the remaining taxa are transferred to four new genera, Planothidium, Rossithidium, Karayevia and Kolbesia. This still leaves a large number of species to be re-allocated and these, for the moment, will have to be left as Achnanthidium sensu lato.

Evolution of reproductive systems in the genus Silene

Abstract: The genus Silene contains both hermaphrodite, gynodioecious and dioecious species, dioecy being represented in three sections of the genus. To locate the events of change of reproductive systems, we compared ITS sequences of 22 species of Silene chosen throughout the whole genus, and four putative outgroup species. Gynodioecy, which is the most common reproductive system within the genus Silene and in closely related genera such as Saponaria and Dianthus , is proposed to be ancestral in the genus. Dioecy has evolved at least twice: once in the section containing S. latifolia , and once in the clade containing S. otites and S. acaulis ssp. bryoides . Evolution towards hermaphroditism, associated with evolution of selfing, has also occurred at least twice, in S. gallica and S. conica .

Molecular genetic analysis.

Abstract: Genetic analysis has long been restricted to a few fungi, especially those that could be easily grown on simple media in the laboratory. The characteristics of the genome in terms of the number of chromosomes and the microscopic morphology of each of these are called the karyotype. In conventional gel electrophoresis DNA molecules smaller than 50 kb can be separated by size. Larger DNA molecules have a minimal velocity that is proportional to their length and therefore separated by size. The patterns produced are highly polymorphic, allowing discrimination between isolates of one species if sufficient primers are screened. The internal transcribed spacer region as well as the intergenic spacer of the nuclear rDNA repeat evolve much faster, and sequence differences in these regions occur between species within one genus or even between different populations of one species.

The genus Amygdalus L. ( Rosaceae ): Species relationships, distribution and evolution under domestication

Abstract: The paper reviews the taxonomic relationships, morphological distinction, geographical distribution and ecological specificities of the twenty six species recognized (by us) in Amygdalus L. It also surveys the intra-genetic structure in this genus stressing the fact that they fall into five groups of closely related vicarious species: (i) Communis group (9 species), (ii) Orientalis group (6 species), (iii) Sect. Chamaeamygdalus (4 species), (iv) Sect. Spartioides (2 species), and (v) Subgenus Dodecandara (5 species). Within each group, species are separated from one another geographically (in few cases by altitude). The only major exception to such allopatric distribution is found in A. communis L., and this is interpreted as an outcome of domestication. Interspecific sterility barriers are absent, or only weakly developed in Amygdalus, and numerous inter-specific hybrids (particularly between the crop and various wild almond species) have been detected. Therefore most (may be all) wild almond species constitute the primary gene-pool of the cultivated nut crop. The combined botanical and archaeological evidene points to the Levant countries as the place where the almond was taken into cultivation. Wild forms of A. communis are very likely native only to this area. Also the earliest archaeological signs of almond domestication come from this area.

Polygenic inheritance of a behavioral phenotype: interspecific genetics of song in the hawaiian cricket genus laupala.

Abstract: The Hawaiian cricket genus Laupala (family Gryllidae) is one of several native genera of flightless crickets found in rain-forest habitat across the Hawaiian archipelago. Species in this genus are morphologically quite similar, but the songs produced by adult males are acoustically distinct. I examined the nature of song variation found within Laupala paranigra and between Laupala kohalensis and L. paranigra, both endemic to the island of Hawaii. Variation within and among species was most notable in the temporal structure of the song, as quantified by the pulse rate. The variation in pulse rate present in natural populations of L. paranigra bred true through the F1 laboratory generation, suggesting that the intraspecific variation in this species has a genetic basis. Interspecific hybridizations between L. kohalensis and L. paranigra successfully produced Fl, F2, and backcross generations. Hybrid F1 males from reciprocal crosses sang with significantly different pulse rates, implicating an X chromosomal contribution to the phenotypic difference between these species. Interspecific patterns of inheritance are most consistent with a type-I genetic ar- chitecture. Polygenic inheritance of the interspecific pulse-rate variation was observed, and approximately eight genetic factors were estimated to underlie the difference in pulse rate between L. kohalensis and L. paranigra.

Monophyly and intrarelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification.

Abstract: A cladistic analysis of interrelationships for 53 (of 58) pleuronectid (Order Pleuronectiformes) species was performed using 106 morphologial and osteological characters. The analysis resulted in a 50% majority-rule consensus tree of 128 equally parsimonious cladograms (heuristic search, 403 steps, ci = 0.33, ri = 0.79). Only five of 47 resolved nodes were observed in less than 100% of the cladograms. These five nodes are restricted to interrelationships within one subfamily. The Pleuronectidae (sensu Chapleau and Keast, 1988) are monophyletic based on ten synapomorphies. In addition, five subfamilies were defined Hippoglossinae, Eopsettinae, Lyonsettinae, Hippoglossoidinae and Pleuronectinae. The largest subfamily, the Pleuronectinae, was further subdivided into four tribes. Psettichyini, Isopsettini, Microstomini and Pleuronectini. The interrelationships established within Pleuronectidae provide a strong foundation for a simplified yet phylogenetically informative taxonomic nomenclature. The genera Atherestes and Reinhardtius; Embassichthys, Errex, Glyptocephalus, Tanakius and Microstomus; Hypsopsetta and Pleuronichthys are regrouped in Reinhardtus; Microstomus and Pleuronichthys, respectively. To preserve the monophyletic status of Eopsetta, E. exilis was reassigned to the genus Lyopsetta (Lyopsettinae). The genus Pleuronectes (as defined by Sakamoto, 1984a) is polyphyletic. It now includes only five species: Pleuronectes glacialis, P. pinnifasciatus, P. platessa, P. putnami and P. quadrituberculatus. Other Pleuronectes species are reclassified in Isopsetta, Limanda, Parophrys, Platichthys, Psettichys, and Pseudopleuronectes. The monophyletic status of the genus Limanda (six species) is uncertain based on unresolved relationships between these species and other taxa in the tribe Pleuronectini.

A catalogue of the nominal species of the monogenean genus Dactylogyrus Diesing, 1850 and their host genera

Abstract: Dactylogyrus is the largest helminth genus, with more than 900 nominal species, and is consequently in a state of considerable confusion. In an attempt to consolidate our knowledge of this large taxon, this work surveys the nominal species and catalogues them and their hosts (to the generic level) in the form of a species list which is cross-referenced to host-parasite list. A reference list to the authorities for the taxa is included.

Host-plant switches and the evolution of chemical defense and life history in the leaf beetle genus oreina

Abstract: Insect-plant interactions have played a prominent role in investigating phylogenetic constraints in the evolution of ecological traits. The patterns of host association among specialized insects have often been described as highly conservative, yet not all specialized herbivorous insect lineages display the same degree of fidelity to their host plants. In this paper, we present an estimate of the evolutionary history of the leaf beetle genus Oreina. This genus displays an amazing flexibility in several aspects of its ecology and life history: (1) host plant switches in Oreina occurred between plant families or distantly related tribes within families and thereby to more distantly related plants than in several model systems that have contributed to the idea of parallel cladogenesis; (2) all species of the genus are chemically defended, but within the genus a transition between autogenous production of defensive toxins and sequestration of secondary plant compounds has occurred; and (3) reproductive strategies in the genus range from oviparity to viviparity including all intermediates that could allow the gradual evolution of viviparity. Cladistic analysis of 18 allozyme loci found two most parsimonious trees that differ only in the branching of one species. According to this phylogeny estimate, Oreina species were originally associated with Asteraceae, with an inclusion of Apiaceae in the diet of one oligophagous species and an independent switch to Apiaceae in a derived clade. The original mode of defense appears to be the autogenous production of cardenolides as previously postulated; the additional sequestration of pyrrolizidine alkaloids could have either originated at the base of the genus or have arisen three times independently in all species that switched to plants containing these compounds. Viviparity apparently evolved twice in the genus, once without matrotrophy, through a retention of the eggs inside the female's oviducts, and once in combination with matrotrophy. We hypothesize that the combination of autogenous defense and a life history that involves mobile externally feeding larvae allowed these beetles to switch host plants more readily than has been reported for highly conservative systems.

Species boundaries, specialization, and the radiation of sponge-dwelling alpheid shrimp

Abstract: Microevolutionary studies and natural history suggest that host-specialization has promoted the high diversity of tropical sponge-dwelling snapping shrimps (Decapoda, Alpheidae, Synalpheus). Yet the taxonomic difficulty of this genus has precluded rigorous tests of this hypothesis. S. rathbunae Coutiere is among the most abundant invertebrates inhabiting the framework of sponges and dead coral that forms the floor of Caribbean coral reefs. Even within a small area S. rathbunae exhibits the apparently wide variation in size, color, and morphology that has long frustrated efforts to identify and define species boundaries within this large ( > 100 described species) genus. Here I show that sympatric populations of this nominal species occupying different sponge hosts display clear, concordant differences in allozyme genotypes and in multivariate morphometrics, confirming that the populations represent three distinct biological species. Moreover, careful field sampling revealed that the three S. rathbunae taxa and the closely related S. filidigitus Armstrong showed almost no overlap in the species of hosts occupied. Interestingly, while there was significant differentiation between Belizean and Panamanian populations of the one taxon that occurred at both sites ( ~ 1500 km apart), these populations were recognizable as conspecific using both genetic and morphological characters. These results show that (1) diversity of Synalpheus, which is already among the most species-rich crustacean genera, is probably several times higher than currently recognized, and (2) species of sponge-dwelling Synalpheus are highly host-specific, with related species distinctly segregated among hosts. Together with previous evidence of host race differentiation within shrimp species, these results suggest a primary role for resource specialization in the origin and/or maintenance of this group's characteristically high diversity.

A revision of the neotropical genus ontherus erichson (coleoptera: scarabaeidae, scarabaeinae)

Abstract: The species of the genus Ontherus, endemic to Latin America, are revised. A key in English and Spanish for the identification of adults of the 58 recognized species is provided. Three subgenera are recognized (Caelontherus nov., Planontherus nov. and Ontherus s.str.). The following 29 species are described as new: O. hadros, O. magnus, O. gilli, O. ashei, O. politus, O. sanctaemartae, O. tenuistriatus, O. obliquus, O. howdeni, O. diabolicus, O. pilatus, O. sextuberculatus, O. lunicollis, O. monilistriatus, O. pseudodidymus, O. rectus, O. pubens, O. ulcopygus, O. cambeforti, O. raptor, O. planus, O. edentulus, O. rectangulidens, O. lobifrons, O. androgynus, O. amplector, O. atlantidis, O. insolitus, O. stridulator. The following new synonymies are proposed (the first specific name being valid): O. kirschii Harold = O. elongatus Waterhouse; O. alexis (Blanchard) = O. didymus Erichson = O. glaucinus Erichson = O. nevinsoni Waterhouse; O. incisus (Kirsch) = O. thoracicus Waterhouse; O. azteca Harold = O. villosus Luederwaldt = O. strius Howden and Young; O. cephalotes Harold = O. quadrituberculatus Luederwaldt. The variety O. zikani var. carinicollis Luederwaldt is now recognized as a valid species. Species are arranged into groups according to their phylogenetic relationship, with a brief diagnosis given for each of the 11 groups of species. The following information is given for each species, when appropriate: detailed literature review, synonymy, description or redescription, illustration of important morphological characters, data of material studied, and geographic distribution.

Variation in fungal endophyte populations in needles of the genus Pinus

Abstract: Endophytic fungi were isolated from the needles of 45 species and varieties of the genus Pinus planted in an arboretum, and the species composition of the endophytes were compared among the pines examined. In general, Leptostroma spp. and Cenangium ferruginosum Fr. ex Fr. were dominant in the middle segment of the needle, while on the basal segment, Phialocephala sp. was more frequently isolated than the other two taxa. Leptostroma spp. seemed to be excluded from the basal segment by Phialocephala sp. The endophytic mycobiota of pines belonging to the same taxonomic group was similar. The taxonomic affinities of the host pines strongly affected the colonization patterns of the endophytes, while the effects of factors such as sampling date, tree age, and location in the stand were much weaker. Keywords: endophytic fungi, Pinus, host preference.

Phylogenetic relationships among the genera of the subtribe Sonchinae (Asteraceae): evidence from ITS sequences.

Abstract: Sequences from the internal transcribed spacer region (ITS) of nuclear ribosomal DNA were used to assess relationships among genera of subtribe Sonchinae (Lactuceae). The data suggest that Sonchinae is paraphyletic, and that the Dendroseridinae should not be recognized as a distinct subtribe. Several Macaronesian genera, along with woody Macaronesian species of Sonchus (all diploid, 2n = 18), appear to have been derived from a common ancestor. Prenanthes pendula is more closely related to this Macaronesian group than to other members of Prenanthes, suggesting that Prenanthes, like Sonchus, is polyphyletic. The Juan Fernandez Islands endemic genus Dendroseris (2n = 36) is monophyletic, but its phylogenetic relationships to other Sonchinae remain uncertain. Reichardia, which forms the sister genus of the Sonchinae, is also monophyletic. Launaea, by contrast, is considered to be paraphyletic. The monotypic genus Aetheorhiza (2n = 18) is sister to the annual weedy species of Sonchus, rather than being closely related to Launaea. Two monotypic endemic genera from New Zealand, Embergeria (2n = 36) and Kirkianella (2n = 90, 126), are sister genera, and together they form the sister clade to Sonchus arvensis-S. maritimus. This implies that these Pacific genera were derived either from section Arvenses or Maritimi of subgenus Sonchus, rather than from section Apseri.

The genus Hippolyte Leach, 1814 (Crustacea: Decapoda: Caridea: Hippolytidae) in the East Atlantic Ocean and the Mediterranean Sea, with a checklist of all species in the genus

Abstract: The genus Hippolyte Leach in the East Atlantic and the Mediterranean is revised and a list of the world species is given. Eleven species occur in the area studied: H. coerulescens (Fabricius), H. garciarasoi spec. nov., H. inermis Leach, H. lagarderei d'Udekem d'Acoz, H. leptocerus (Heller), H. leptometrae Ledoyer, H. niezabitowskii spec. nov., H. palliola Kensley, H. prideauxiana Leach, H. sapphica d'Udekem d'Acoz, H. varians Leach. An elaborate key, complete descriptions and illustrations of all species are provided, while their ecology is discussed in detail. A morphological account is also given for the species occuring in the Suez Canal: H. proteus (Paulson) and H. ventricosa H. Milne Edwards. It is shown that H. prideauxiana (previously H. huntii) and H. varians display important geographical variations. H. longirostris proves to be a junior synonym of H. leptocerus but part of the specimens previously referred to as H. longirostris belong in fact to a new species: H. garciarasoi spec. nov. The latter is not very variable but it is extremely close to H. leptocerus which itself displays extraordinary variations within individual populations and on a geographical scale. H. sapphica presents discontinuous variations: it comprises a long-rostred form (forma A) and a short-rostred form (forma B). H. niezabitowskii spec. nov. is a new species possibly endemic in the Adriatic and Ionian Seas and morphologically close to H. inermis and to the Mediterranean populations of H. varians. H. coerulescens presents some neotenic characters.

O gênero Miconia Ruiz & Pav. (Melastomataceae) no Estado de São Paulo

Abstract: The present paper deals with the species of Miconia occuring in the Brazilian State of Sao Paulo. The 53 species listed and described here probably represent all taxa of the genus collected in this State.

Revision of the dioecious genus chersodoma phil. (Senecioneae, Asteraceae), including a new species and status change

Abstract: A revision of the dioecious genus Chersodoma (Senecioneae, Asteraceae) recognizes nine species, including a new species, C. deltoidea Sagast. & M. O. Dillon, from northern Peru and a status change for a northwestern Argentine endemic, C. glabriuscula (Cabrera) M. O. Dillon & Sagast. Chersodoma is confined to the Andean Cordillera and is the only dioecious member of the Senecioneae in continental South America. A cladistic analysis of a morphological data set supports the monophyly of the genus and the recognition of two previously established subgenera. Subgenus Chersodoma contains three species (C. argentina, C. candida, C. jodopappa) with greatest diversity in the semi-arid puna of northwestern Argentina and adjacent Bolivia and Chile. Subgenus Diclinanthus B. Nord., contains six species (C. antennaria, C. arequipensis, C. deltoidea, C. juanisernii, C. glabriuscula, and C. ovopedata) with greatest diversity in Peru. A key to Andean genera of Senecioneae is provided. A discussion of species relationships and historical biogeography is presented as suggested by morphological parsimony analysis.

Redefinition of the neotropical genus Anthopterus (Ericaceae: Vaccinieae), including one new species

Abstract: The taxonomic history of Anthopterus as it relates to Themistoclesia is briefly reviewed. Anthopterus is redefined to include several species formerly placed in Themistoclesia. Two subgenera are established within Anthopterus. Anthopterus costaricensis Luteyn is described as new, and the new combination Anthopterus pterotus (A. C. Sm.) Luteyn is made. A key to the genus, a list of the species currently accepted, and brief notes on distribution and frequency are provided. Most species of Anthopterus are rare and their habitats are endangered.

A revision of the genus Nothosaurus (Reptilia: Sauropterygia) from the Germanic Triassic, with comments on the status of Conchiosaurus clavatus

Abstract: 1