Revisione delle specie: Actinomyces albus,A. chromogenus,A. odorifer,A. thermophylus,A. viridis,A. viridochromogenes,A. hominis,A. innominatus

Riassunto Lo studio comprende una revisione critico-sperimentale della specie Actinomyces albus, della quale vengono considerati come sinonimi circa 30 nomi speeifici, fra i quale A. chromogenus, A. odorifer, A. thermophylus p.p.; della specie é data una diagnosi ed una particolareggiata descrizione.Sono inoltre studiate le specie A. viridis, (= A. viridochromogenus) e A. innominatus, n. nomen. Quest'ultima é preceduta da una breve discussione sulla specie A. homini.

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Summary Twenty-six strains of Actinomyces albus are studied redescribed from morphological, cultural and biochemical standpoints. Many biological activities of A. chromogenus, A. odorifer and A. thermophilus are in common with other species of the same genus, so that they may be considered for sub-specific, (not specific) differentiation. A discussion on A. farcinicus, A. albidoflavus and A. aureus has been originated from mislabeling as A. albus; the group including the two last named species (flavus group) must be revised. A few strains classified A. farcinicus are in no doubt true A. albus, but this real specific entity remains to be revised from Nocard's strain. A. viridis, for the first time described by Lombardo-Pellegrino, has been redescribed three times as a new species under the same binomial, and the fourth as A. viridochromogenes. A. hominis Bostroem is an uncorrect determination for the species originally described by Waksmann and Curtiss, and it is renamed A. innominatus, the binomial A. (Streptothrix) hominis Auct. being a nomen ambiguum. In conclusion, 30 bionmial are appended in sinonimy to A. albus, including Cladothrix dichotoma Macé (1888) non Cohn, G. invulnerabilis Acosta et G. Rossi, C. odorifera Rullm. Actinomyces chromogenus Gasp., A. thermophilus Auct., p.p., A. (Streptothrix) Sanninii (Cif.) Westerd., A. Almquisti Duché, A. Gougeroti Duché, and so on.

     

The genusAntennaria (Asteraceae: Inuleae) in western North America: Morphometric analysis ofAntennaria alborosea,A. corymbosa,A. marginata,A. microphylla,A. parvifolia,A. rosea,andA. umbrinella

Multivariate analysis of vegetative and reproductive characters was used to examine morphological relatedness amongAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels.,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt.,A. rosea Greene, andA. umbrinella Rydb. Both pistillate and staminate plants were examined. Some of the characters examined were variable in one species, but stable in another (i.e., presence or absence of papillae on the achenes). Our analyses indicate that the seven species are morphologically distinct. It is hypothesized that theA. rosea agamic complex arose through hybridization amongA. corymbosa, A. microphylla, A. umbrinella, and possiblyA. dioica (L.)Gaertn. However, hybridization between the three former species and others, as well as their subsequent morphological responses to different environmental conditions causes confusion in recognizing the taxa.Antennaria angustifolia Rydb.,A. arida E. Nels.,A. confinis Greene,A. scariosa E. Nels.,A. foliacea humilis Rydb.,A. concinna E. Nels., andA. viscidula E. Nels. are considered to represent F 1 hybrids.     

Patterns of intraspecific variation inAntennaria alborosea,A. corymbosa,A. marginata,A. microphylla,A. parvifolia,andA. umbrinella (Asteraceae:Inuleae)

Patterns of intraspecific variation were examined inAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt., andA. umbrinella Rydb. AlthoughA. alborosea was initially considered arctic in distribution, it became apparent that a southern montane element also exists. Our results suggest that morphological differences between arctic and southern montane specimens represent clinal variation. The additional morphological data for specimens that occur more than 1,500 km south of the species' range as it was initially described result in a better understanding of this once presumed arctic taxon. Morphological variation in the dioecious speciesA. corymbosa, A. marginata, A. microphylla, A. parvifolia, andA. umbrinella was greater between the genders than was geographic variation within each gender. These results demonstrate that both pistillate and staminate specimens must be examined in dioecious species ofAntennaria if morphological variation in the respective species is to be fully understood. Character size or number of broadly distributed species (A. microphylla andA. parvifolia) generally decreased with increasing longitude, whereas characters of species with more restricted distributions (A. alborosea, A. corymbosa, andA. marginata) generally increased in size or number with increasing latitude or longitude.Antennaria umbrinella was an exception in this respect.     

Evaluation of taxonomic validity of four species of Acanthamoeba: A. divionensis, A. paradivionensis, A. mauritaniensis, and A. rhysodes, inferred from molecular analyses

The taxonomy of Acanthamoeba spp., an amphizoic amoeba which causes granulomatous amoebic encephalitis and chronic amoebic keratitis, has been revised many times. The taxonomic validity of some species has yet to be assessed. In this paper, we analyzed the morphological characteristics, nuclear 18s rDNA and mitochondrial 16s rDNA sequences and the Mt DNA RFLP of the type strains of four Acanthamoeba species, which had been previously designated as A. divionensis, A. parasidionensis, A. mauritaniensis, and A. rhysodes. The four isolates revealed characteristic group II morphology. They exhibited 18S rDNA sequence differences of 0.2-1.1% with each other, but more than 2% difference from the other compared reference strains. Four isolates formed a different clade from that of A. castellanii Castellani and the other strains in morphological group II on the phylogenetic tree. In light of these results, A. paradivionensis, A. divionensis, and A. mauritaniensis should be regarded as synonyms for A. rhysodes.