Life history of Japanese Stypocaulon durum (Sphacelariales, Phaeophyceae)

Phenology, morphology, life history and responses to different temperature and photoperiod conditions were studied in Japanese Stypocaulon durum (Ruprecht) Okamura. Erect thalli of the species were collected year-round, but the mature thalli forming either uniloc-ular sporangia or two different types of plurilocular structures (evidently gametangia) on separate thalli were found only in winter. ln culture, an isomorphic life history is suggested for the species, alternating between a sporophyte forming unilocular sporangia and gam-etophytes forming plurilocular macro- (female) and micro- (male) gametangia. Contents of unilocular sporangia were not released, but germinated in situ, developing into erect thalli forming plurilocular gametangia. Macrogametangia released aplanogametes (oospores), but male gametangia appeared to be non-functional, although flagellated cells were once formed in the loc-uli. This is the first report of plurilocular gametangia in the species. Although the species grew well and matured under considerably lower temperature conditions than European Stypocaulon scoparium (L.) Sauvageau, its temperature requirements showed similarity to northwestern Atlantic Stypocaulon species. This supports the notion that northwestern Atlantic Stypocaulon is conspecific with S. durum.     

A critical rebuttal of the proposed division of the genus Arcobacter into six genera using comparative genomic,phylogenetic, and phenotypic criteria

The proposal to restructure the genus Arcobacter into six distinct genera was critically examined using: comparative analyses of up to 80 Epsilonproteobacterial genome sequences (including 26 arcobacters); phylogenetic analyses of three housekeeping genes and also 342 core genes; and phenotypic criteria. Genome sequences were analysed with tools to calculate Percentage of Conserved Proteins, Average Amino-acid Identity, BLAST-based Average Nucleotide Identity, in silico DNA–DNA hybridisation values, genome-wide Average Nucleotide Identity, Alignment Fractions and G + C percentages. Genome analyses revealed the genus Arcobacter sensu lato to be relatively homogenous, and phylogenetic analyses clearly distinguished the group from other Epsilonproteobacteria. Genomic distinction of the genera proposed by Pérez-Cataluña et al. [2018] was not supported by any of the measures used and a subsequent risk of strain misidentification clearly identified. Similarly, phenotypic analyses supported the delineation of Arcobacter sensu lato but did not justify the position of the proposed novel genera. The present polyphasic taxonomic study strongly supports the continuance of the classification of “aerotolerant campylobacters” as Arcobacter and refutes the proposed genus-level subdivision of Pérez-Cataluña et al. [2018].     

A new infrafamilial taxonomic setting for Liliaceae,with a key to genera and tribes

Based on currently available morphological, karyological, and phylogenetic information, a taxonomic setting of Liliaceae is provided. The family is here organized in 6 tribes, for a total of 15 genera and about 900 species. An identification key for tribes and genera is also provided.     

Justification for the generic status of Courtoisina (Cyperaceae)

In the past, the two species of Courtoisina were placed either in Cyperus L., Mariscus Vahl, or in Courtoisia Nees (now Courtoisina Sojak). While these species show undoubted external similarities to both Cypm and Muriscus , they differ by their widely winged glumes and the arrangement of the veins of the glumes. They also differ profoundly from Mariscus and most species of Cypm in anatomical characteristics, and it is concluded that these differences warrant separate generic status.     

A numerical taxonomic study of some pigmented bacteria isolated from Organic Lake,an antarctic hypersaline lake

A study was made of a group of moderately halophilic, heterotrophic, pigmented strains isolated from Organic Lake, Antarctica. These strains were Gram-negative, non-motile, had an aerobic metabolism and a mol% G+C content of their DNA in the range 35–41, indicating that they may be members of the Flavobacterium-Cytophaga group. A numerical taxonomic study involving 134 characteristics compared the antarctic strains with reference strains from Flavobacterium, Cytophaga and Flectobacillus. The antarctic strains formed two clusters that did not contain any reference strains suggesting that they may represent two new species of the genus Flavobacterium.     

Carayonovus n. gen. from Reunion Island – aberrant new genus of Anthocoridae or representative of a new family (Heteroptera: Cimicoidea)?

Carayonovus insignis n. gen., n. sp., a remarkable new genus and species of Heteroptera, is described from Reunion Island. It is tentatively placed in the family Anthocoridae (Cimicoidea), but because of its remarkable sexual dimorphism and possession of characters not normally associated with this family or even with Cimicoidea, the genus is discussed in terms of the validity or otherwise of including it in these taxa. Its habitat preference is also examined.     

Flow cytometric,chromosomal and morphometric analyses challenge current taxonomic concepts in the Portulaca oleracea complex (Portulacaeae,Caryophyllales)

Portulaca oleracea is a noxious annual weed of worldwide distribution in temperate to tropical climates. Its taxonomy has been treated in contradictory ways in the past. Various microspecies have been described, lumped into a single species by other authors. We re‐examined the importance of seed size and ploidy variation, previously applied as the most important taxonomic characters, for systematic classification based on accessions from Europe, Asia, Africa and South America using flow cytometry, chromosome counting and morphometry. Sixteen microspecies and six transitional forms, covering the ploidy and seed character variation, proposed for the complex, were studied from 178 populations. Portulaca grandiflora was included as a reference species from outside the complex. DNA hyper‐pentaploidy or hexaploidy were inferred for the majority of accessions which exhibited the full range of seed size. It is recommended that the only species of lower ploidy (either diploid based on x = 12 or tetraploid based on x = 12) encountered, P. nicaraguensis, should be separated from the P. oleracea complex as it deviates in base chromosome number and monoploid genome size. The frequency distribution of seed size was continuous and unimodal within the wild taxa of the complex and in pairs of taxa defined by testa sculpture. Seed size of DNA hexaploids was slightly negatively correlated with sample/standard fluorescence intensities. Our results conflict with the current microspecies concept. Possible reasons underlying the discrepancy are discussed and strategies for future systematic research are suggested. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 144–156.