A new variety of Draba pedicellata and a lectotype for D. cusickii (Brassicaceae)

A closely related group of Great Basin endemic dradas,Draba cusickii O. E. Schulz,D. sphaeroides Payson, andD. pedicellata (Rollins & R. A. Price) Windham, are described, keyed, and discussed in order to putD. pedicellata var.wheelerensis N. H. Holmgren, var. nov. in perspective.Draba cusickii is endemic to Steens Mountain of southeastern Oregon, andD. sphaeroides is known only from three mountain ranges in Elko County, Nevada, whereasD. pedicellata is more widespread in mountain ranges of eastern Nevada in Elko, Eureka, Nye, and White Pine counties.Draba pedicellata var.pedicellata occupies most of the range of the species, with var.wheelerensis being restricted to the Snake Range, just to the east of the range of the typical variety.     

ORIGINAL ARTICLE: Cycads in the insular South‐west Pacific: dispersal or vicariance?

Aim Cycads constitute an ancient plant group that is generally believed to disperse poorly. However, one group of cycads (subsection Rumphiae) is thought to have dispersed relatively recently from a Malesian source area westwards to East Africa and eastwards into the Pacific, using a floatation‐facilitating layer in their seeds. We use morphological and allozyme characters to investigate the relationships among the species within this group and to deduce whether the wide distribution was achieved by recent dispersal (as evidenced by high genetic similarity) or more distant vicariance events (high genetic differentiation). Location We examined specimens collected throughout the range of subsection Rumphiae, from East Africa through Southeast Asia to Tonga in the South‐west Pacific. Methods We investigated relationships within subsection Rumphiae of the genus Cycas by analysing 18 variable (11 informative) morphological characters and 22 allozyme loci for seven of the 10 species currently assigned to this taxon. Results Distinctive morphological characters are few and fail to resolve relationships within the group. Allozyme data show that species within this subsection are closely related and suggest that there are two groups within the subsection, one comprising Cycas thouarsii (East Africa) and C. edentata (the Philippines), and the other the remaining species (from Malesia and the Pacific). The Australian species C. silvestris is sister to subsection Rumphiae in the morphological analysis but is closely allied to C. rumphii (nested within the subsection) in the allozyme analysis, suggesting that Rumphiae may be paraphyletic and that characters thought to be taxonomically important may need to be re‐evaluated. Main conclusions Cycads within subsection Rumphiae are closely related, and the wide distribution of this group was probably achieved through relatively recent oceanic dispersal events. Separate events probably account for the dispersal of these cycads into the Pacific and to Africa. The origin and distribution of C. silvestris (Australia) could be explained by a dispersal event from New Guinea or may have resulted from a former land connection between Australia and New Guinea.     

Molecular phylogeny of the subgenus Holothuria (Selenkothuria) Deichmann, 1958 (Holothuroidea: Aspidochirotida)

The subgenus Selenkothuria comprises 12 species of tropical shallow water sea cucumbers that share morphological features, such as rods in the body wall and tube feet, modified tentacles for suspension feeding, and cryptic colours. The taxonomic status of this taxon has been controversial, but currently it is accepted as a subgenus of the genus Holothuria. Phylogenetic analyses of mitochondrial genes [cytochrome c oxidase subunit 1 (COI), 16S RNA] of ten species of Selenkothuria and related subgenera showed the polyphyly of this subgenus; monophyly was rejected by a likelihood ratio test. A geographical split divides the species of this subgenus into three different groups: one Indo‐West‐Pacific (IWP) group and two American groups. The IWP group is more closely related to Holothuria (Semperothuria) cinerascens and to other subgenera such as Roweothuria, Holothuria, and Vaneyothuria, whereas the two American groups are more closely related to each other and to some species of the subgenus Halodeima. These results suggest multiple parallel originations and diversification of ossicle morphology within the subgenus Selenkothuria. The current scheme of subgenera for the genus Holothuria is not supported, suggesting the need for a new classification. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 109–120.     

THE ORIGIN AND EVOLUTIONARY RELATIONSHIPS OF ‘HUAUZONTLE’ (CHENOPODIUM NUTTALLIAE SAFFORD), DOMESTICATED CHENOPOD OF MEXICO

A New World assemblage of tetraploid Chenopodium species (section Chenopodium, subsection Cellulata) includes two domesticates, C. quinoa of Andean South America and C. nuttalliae of Mexico. Both have been combined into a single species and the Mexican form has been considered as a possible derivative of C. quinoa. The domesticates and related, sympatric weed forms, C. berlandieri of North America and C. hircinum of the Andes, were examined for variation in morphological and biochemical characteristics and also were included in a program of artificial hybridization. Results indicate that the domesticated forms are more closely related to their sympatric weeds than to each other. The Mexican cultigen is placed as a subspecies of C. berlandieri, the taxon from which it most likely evolved under human selection in North America. Possible origins for the Andean weed-crop complex are considered. Southward migration of a North American tetraploid appears to be more likely than independent allotetraploidy in South America. Of the North American tetraploids examined, C. berlandieri var. zschackei of the western U.S. shows closest affinities to the Andean complex.     

PATTERNS OF GENETIC VARIATION IN SALIX SECTION LONGIFOLIAE (SALICACEAE)

Enzyme electrophoresis was used to examine genetic relationships within a taxonomically complex group of diploid willows (Salix section Longifoliae). Forty-eight populations representing seven morphogeographic taxa were analyzed for 15 putative enzyme loci. Levels of genetic variation (A, P, H_e, and H_T) differed greatly among populations, but were generally lower than those reported for other species with similar life history traits. In populations and species from southern latitudes, where populations tend to be smaller and more isolated, genetic variation decreased and population differentiation increased. Genetic identity values suggest that the section is divisible into four major elements: 1) Salix interior, 2) S. taxifolia, 3) the S. exigua group, and 4) S. melanopsis. The first three occupy eastern, southern, and western portions of the continent, respectively. Salix melanopsis is sympatric with the S. exigua group in western North America, but is ecologically distinct. The S. exigua group is differentiated into four major geographic entities: S. hindsiana from west of the Sierras in California and southwest Oregon, S. sessilifolia from west of the Cascades in central Oregon to British Columbia, and a northern and southern race of S. exigua in the Intermountain West. The relationships suggested by allozyme data do not agree with traditional taxonomic concepts. Evidence of hybridization was obtained at five points where taxa come into contact, and Salix fluviatilis may be of hybrid origin. Taxonomic confusion appears to be largely the result of frequent hybridization events and overemphasis of a few highly variable morphological traits. The section appears to be a syngameon undergoing geographic speciation, with one taxon gaining reproductive isolation by a shift in habitat preference.     

Seven new species and two new subspecies of Sclerocypris SARS, 1924 from Africa,with new records of some other Megalocypridinids (Crustacea,Ostracoda)

Sclerocypris dayae n.sp., S. dedeckkeri n.sp., S. dumonti n.sp., S. zelaznyi n.sp. and S. zelaznyi etoshensis n.ssp. are described from South — West Africa (Namibia). S. exserta makarikarensis n.ssp. originates from the endorheic pan system Makarikari in Botswana. S. woutersi n.sp. was described from Lake Albert where it is quite common. S. virungensis n.sp. is known from the Virunga National Park, south of Lake Edward (Zaire). The latter two species are closely related and from part of the flabella-species group. S. longisetosa n.sp., described from a marsh near Kisumu (Kenya), is an enigmatic species, holding an isolated position in the genus due to an aberrant T1.Present address: Rijksuniversiteit Gent, Laboratorium voor ecologie der dieren, zoögeografte en natuurbehoud (Institute for Ecology), K. L. Ledeganckstraat 35, B9000 Gent, Belgium.     

Alpinia newmanii sp. nov. (Zingiberaceae) from central Vietnam

Alpinia newmanii, a new species from central Vietnam, is described and illustrated. A morphological comparison with the most closely related species and a key to the species of Alpinia subsection Catimbium in Vietnam are provided.     

PHYLOGENETIC IMPLICATIONS OF DIFFERENCES IN NUMBER OF PLASTID PHOSPHOGLUCOSE ISOMERASE ISOZYMES IN NORTH AMERICAN COREOPSIS (ASTERACEAE: HELIANTHEAE: COREOPSIDINAE)

Enzyme electrophoresis was employed to ascertain the number of loci encoding plastid phosphoglucose isomerase (PGI) in species representing all sections of North American Coreopsis. Several species from each of the closely related genera Bidens, Coreocarpus, Cosmos, and Thelesperma were also examined. Species in nine of the 11 sections of North American Coreopsis have two isozymes for plastid PGI, and nearly all species examined in the four other genera also have two (one species has three) isozymes. Since most diploid vascular plants have one plastid PGI isozyme, a gene duplication probably occurred in an ancestor that is common to Coreopsis and the other four genera. That is, two isozymes represent the ancestral number for Coreopsis. The two sections (Electra and Anathysana) apparently lacking the duplication are closely related woody plants restricted largely to Mexico. One gene encoding plastid PGI ostensibly was silenced in a common ancestor of these two sections. This is concordant with other data suggesting a close relationship between the two sections, i.e., they appear to represent a monophyletic group. The electrophoretic data also indicate that 1) the enigmatic monotypic section Silphidium is more closely related to eastern North American sections and not derived from section Electra; and 2) section Anathysana is not ancestral to the three California sections Leptosyne, Pugiopappus, and Tuckermannia; rather, it represents a terminal element closely related to and possibly derived from section Electra.     

On Barbula munyensis R.S.Williams (Pottiaceae), an overlooked species from the tropical montane forest of South America

Abstract

Barbula munyensis R.S.Williams, a neglected moss species known only from the type material collected in central Peru in 1923, is newly reported for the moss floras of Argentina and Bolivia. The species is described, illustrated, mapped, and its habitat preferences are provided. Diagnostic characters and differentiation from some closely related South American taxa, with which it may be confused, are discussed. Barbula orizabensis Müll.Hal., a similar taxon, is excluded from the South American moss flora.     

Notes on <Emphasis Type="Italic">Swartzia</Emphasis> (Leguminosae) in Central America preliminary to the Flora Mesoamericana,with descriptions of two new species from Costa Rica

In preparation of a treatment of Swartzia (Leguminosae) for the Flora Mesoamericana, recent updates to the taxonomy of the genus in Central America are discussed, and two new species from the Pacific slope and lowlands of central and southern Costa Rica are described and illustrated. One of them, S. picramnioides, is a member of the section Possira and is closely related to S. standleyi of Guatemala and Belize and to the South American species S. myrtifolia. The other, S. zeledonensis, belongs to the Central American apetalous clade of section Terminales. It is probably most closely related to the Panamanian species, S. nuda. We conclude that Swartzia is represented in Mexico and Central America by 14 species and provide a key for their identification.     

A phylogeographic study of the cosmopolitan genus Phragmites (Poaceae) based on AFLPs

Within the genus Phragmites (Poaceae), the species P. australis (the common reed) is virtually cosmopolitan, and shows considerable variation in ploidy level and morphology. Genetic variation in Phragmites was studied using AFLPs, and analysed with parsimony and distance methods. Groups of P. australis strongly supported in the analyses include one that comprises all South American clones, a distinct group from the US Gulf Coast, and a group of E. Asian and Australian octoploids. Among the other species, the paleotropical P. vallatoria is supported as monophyletic and most closely related to the paraphyletic P. mauritianus and to the Gulf Coast and S. American groups. The E. Asian species P. japonicus is closely related to a group of P. australis clones mostly from central North America. Tetraploidy predominates in the genus, and optimisation of chromosome numbers onto the phylogeny shows that higher ploidy levels have evolved many times.     

Multiple effects of precipitation onSalix lasiolepis and populations of the stem-galling sawfly,Euura lasiolepis

Relatively low winter precipitation (e.g., 18–28 cm from October to May compared to 45 to 65 cm) caused reduced growth of the arroyo willow,Salix lasiolepis, with number of shoots per stem initiated and shoot length reduced. Resources were reduced for the stem-galling sawfly,Euura lasiolepis, which declined in numbers after the relatively dry winter of 1980–81. Sawfly phenology was advanced relative to willow phenology in the 1981 generation, causing an additional reduction in resource availability. These direct effects of precipitation on the sawfly were increased by indirect effects on survivorship of the 1981 generation. Egg death in galls increased on water-stressed willow plants, forming the major mortality in the generation. This resulted in very low survival in the generation and an even lower population in the 1982 generation, even though resources recovered after high precipitation during the 1981–82 winter (46.7 cm). An experiment using high, medium, and low water treatments on potted willow plants demonstrated that the effects on willows and sawflies could be reproduced using only water as a variable.     

Typification of Pallas’ names in <Emphasis Type="Italic">Salix</Emphasis>

Summary  The original collections of Salix species described by Pallas are discussed. Eight names validated by Pallas and one by Nasarov are typified. The use of six currently accepted names, S. arbutifolia Pall., S. arctica Pall., S. berberifolia Pall., S. caspica Pall., S. divaricata Pall. and S. rhamnifolia Pall., is confirmed. Salix serotina Pall. retains its place as a synonym of S. viminalis L. Salix gmelinii Pall. is resurrected and proposed as the correct name for the taxon previously known as S. dasyclados Wimm. S. burjatica Nasarow and S. jacutica Nasarow, the old synonyms of S. dasyclados, therefore are now also synonyms of S. gmelinii. A new combination S. rosmarinifolia L. subsp. sibirica is proposed.     

Factors influencing forage selection by the North American beaver (Castor canadensis)

Across their range, a large number of biotic and abiotic factors are known to influence the choice of browse plant and the foraging behaviour of the North American beaver (Castor canadensis). We used generalized linear mixed-effects models to investigate sets of variables that may influence the foraging choices of beaver: forage species, distance of forage from water, forage density, and site. Communities across the study sites in central British Columbia, Canada, were dominated by Salix sitchensis, Salix lucida, and Alnus spp. Density had no impact on forage selection, while site, distance from water, and species identity all influenced the foraging decisions of beaver. We postulated that these factors may be ordered hierarchically: large-scale factors, such as site, followed by the medium-scale distance from water, and species of plant at the finest scale. Forage items in some sites had a higher probability of being browsed than in others, while in all sites the probability of being browsed decreased with increasing distance from water. Beaver appeared to be foraging as “picky” generalists; of the 9 plant species examined, 3 species of Salix (S. scouleriana, S. drummondiana and S. sitchensis) were selected by beaver, Salix bebbiana was avoided, and 5 species were neither selected for nor against. Browse selection within the genus Salix implied that beaver were able to differentiate among closely related species. Detailed information on forage selection is a crucial first step in designing and interpreting models that predict large-scale distributional patterns of beaver.     

Karyomorphology of Sorghum propinquum and its bearing on the origin of 40-chromosome sorghum

Summary Pachytene morphology of S. propinquum has been studied on the basis of chromosome length, centromere position and the distribution of deeply staining regions on the chromosome. The present species which belongs to the subsection Halepensia differs from the species of the subsection Arundinacea in that the nucleolus is organized by the shortest chromosome of the complement while in the latter group the nucleolar chromosome is the longest. The significance of this difference in evaluating the probable role of S. propinquum in the origin of 40-chromosome species of Sorghum has been considered.     

New species of the genus Salganea (Blattaria, Blaberidae, Panesthiinae) from Myanmar, with molecular phylogenetic analyses and notes on social structure

A new species of the genus Salganea is described from Mount Victoria, Chin State, Myanmar under the name of Salganea matsumotoi sp. nov. Morphological investigation suggests that this species belongs to the S. nigrita species group. The inferred molecular phylogenetic tree indicates that S. matsumotoi is most closely related to the taxa S. incerta, S. taiwanensis, S. gressiti and S. esakii, distributed in Thailand, Taiwan and Japan, all of which belong to the S. nigrita species group. Social structural data suggest that this species is subsocial, and in contrast to other studied species in the genus, potentially has more than one reproductive episode.     

Studies on Bacteriophage Distribution

Twenty-eight bacteriophage strains active on one or more species of Enterobacteriaceae were isolated from sewage and were classified into seven host range groups. Two isolates resemble S13, three isolates appear to be closely related to T₁, and one seems to be related to T even phages. Members of one host range group are active on three bacterial species, viz., Escherichia coli, Salmonella typhimurium, and Shigella sonnei. Some of the E. coli K12 strains selected for resistance to phage HK019 are sensitive to S13 but not to φ×174.