Plant invasions, interspecific hybridization and the evolution of new plant taxa

Interspecific hybridization between a native and an invading plant species, or two invading species, sometimes results in a new, sexually reproducing taxon. Several examples of such taxa have been confirmed by recent molecular and isozyme analyses. Further study of these new taxa, when recognized soon after their origin, should aim to elucidate the factors that influence their subsequent establishment and spread, thus leading to a better understanding of the processes that lead to successful speciation. Plant hybrids formed following a plant invasion provide great potential for the study of ‘evolution in action’.     

Some new taxa of desmids from the Andaman Islands,India

Two new species, five new varieties and five new forms belonging to the desmid genera Closterium Nitzsch, Pleurotaenium Naeg., Euastridium W. & W., Micrasterias Agardh, Cosmarium Corda and Staurastrum Meyen from the Andaman Islands are described.     

Two new taxa of Spirogyra

Summary A new species and a new variety ofSpirogyra have been recorded.Spirogyra varshaii spec. nov. has been described and compared to two related species ofSpirogyra. This species has a very distinct subdenticulate to denticulate type of ornamentation of the zygospore wall and differs from the other two related speciesS. chakiense andS. verruculosa in having different dimensions of the zygospores and in the number of chloroplasts. A new variety,Spirogyra chakiense var.lucknowense var. nov. has been described. It differs from the speciesS. chakiense in possessing some differences in the dimensions of the cells and the zygospores from the type species.

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Zusammenfassung Eine neue Spezies und eine neue ArtSpirogyra sind eingetragen worden.Spirogyra varshaii Spec. nov. ist beschrieben worden und mit zwei verwandten Spezies verglichen. Diese Spezies hat einen sehr deutlichen unterzahnigen bis zum zahnigen Typus der gestickten Zygosporeswand, und sie unterscheidet sich von den anderen zwei verwandten SpeziesS. chakiense undS. verruculosa daß sie verschiedene Ausdehnungen der Zygosporen und auch eine verschiedene Zahl der Kromatophoren hat. Eine neue ArtSpirogyra chakiense var.lucknowense var. nov. ist auch beschrieben worden. Sie unterscheidet sich von der SpeziesS. chakiense weil sie einigen Unterschieden in Ausdehnungen der Zellen und auch der Zygosporen hat im Vergleich mit der Typusspezies.

     

Names of new taxa and new names for known taxa,a current problem in the communication between taxonomists and users—What to do?

An updated list is given of new bacterial names published in 1994, that are of interest for medical and/or veterinary bacteriologists.     

Some new taxa ofPotentilla L.

Five new species and two varieties from the sectionMultifidae are described from the Sino-Himalayan region. They are referred to the affinity ofP. multifida L. andP. griffithii Hook. f.; one of the new species is probably related toP. gerardiana Lindl. and one is intermediate between the species of the sectionsMultifidae andNiveae.     

Lignicolous dematiaceous hyphomycetes in Japan: five new records for Japanese mycoflora, and proposals of a new name, Helminthosporium magnisporum, and a new combination, Solicorynespora foveolata

Through investigations on dematiaceous hyphomycetes on dead ligneous plant substrata, mainly in northern Japan, five species were newly added to the Japanese mycoflora: Corynespora trichiliae, Diplococcium stoveri, Ellisembia folliculata, Monodictys melanopa, and Paratomenticola lanceolata. Morphological characters with line drawings and cultural characteristics of these anamorphic fungi are reported. A new name, Helminthosporium magnisporum for H. gigasporum, and a new combination, Solicorynespora foveolata for H. foveolatum, are proposed.     

James Stirton's new Racomitrium taxa revised

Abstract

Lectotypes are selected of six mosses described by James Stirton. Grimmia sublunda, G. calvescens and G. papillulata are synonyms of Racomitrium sudeticum; R. heterostichum var. amblyphyllum and R. divergens are synonyms of R. heterostichum; Grimmia fuscoviridis is a synonym of Racomitrium ellipticum; and R. consocians is a synonym of R. ericoides.     

内蒙古高原土壤中的暗色丝孢菌

从内蒙古高原及河套地区不同生境中,采集混合土样52份。分离获得51个暗色丝孢菌菌株,经鉴定分隶于18属27种。其中包括1个新种,贺兰山小镰孢Fusariella helanshanensis和1个中国新记录种,葫芦细基格孢Ulocladium cucurbitae。除新种具拉丁文特征集要和图示、对中国新记录种作简要描述和绘图外,25个国内已报道种附有分布和生境的引证。所有供研究标本(干制培养物)与活菌种,均保存于山东农业大学植物病理学标本室(HSAUP)。     

Five new taxa in Eriocaulaceae from the Chapada Diamantina of Bahia,Brazil

Five new taxa in Eriocaulaceae from the Chapada Diamantina of Bahia, Brazil are described and illustrated and their diagnostic characters discussed and compared with other similar taxa. Eriocaulon ligulatum var. dimerum occurs only between Len?óis and Palmeiras; Paepalanthus carvalhoi occurs in Palmeiras, Mucugê and Barra da Estiva; P. umbrosus, P. multicapitatus and P. oblongifolius are known only from the Serra da Chapadinha near Len?óis.     

A new algorithm for the determination of differential taxa

Question: How can we determine differential taxa in a vegetation data set? Methods: The new algorithm presented here uses an intuitive fidelity threshold based on relative constancy differences. It is tested on a simulated and a real data set. The results of the proposed algorithm are discussed in comparison with other methods used for the determination of differential taxa. Results: The new algorithm defines each taxon in each group of relevés as: (1) positively differentiating, (2) positively‐negatively differentiating, (3) negatively differentiating, or (4) non‐differentiating. Each taxon in a data set may be: (1) positively, positively‐negatively or negatively differentiating for each group in the data set, (2) differentiating for some groups and non‐differentiating for the remaining groups, or (3) non‐differentiating for all groups in the data set. Conclusions: The new algorithm finds the relevé groups that are positively differentiated against other groups that are negatively differentiated. It reveals differentiating structures in the data set and thus makes quantification of the relations among and between different syntaxonomic ranks conceivable. As it distinguishes between different types of differential taxa, it might improve standards of typification in vegetation classification.     

Additional new taxa ofRubiaceae for the Flora of Turkey

A new species ofCruciata and a new subspecies ofGalium are described and discussed with regard to their affinities. Two new combinations are required for geographical races ofRubia tenuifolia. Galium lovcense Urum. has priority overG. protopycnotrichum Ehrend. & Krendl.     

Some new taxa of Nitelleae from Yunnan

Yunnan is extends across the subtropical and tropical zones, situated in the southern border area of southwestern China. This district is extremely rich in plants, and thus, it has been known as a “Kingdom of Plants”. However, up to the present our knowledge of the Charophyta in this region has been scanty. In order to get a thorough understanding of its Charophyta, we identified specimens collected from 13 countries or cities in this province. The result shows that is especially abundant in Charophyta. In this paper, however, only are reported new species, new varieties and new records of China on the Nitelleae. The former two are Nitella hokouensis, N. bicornuta, N. longicaudata, N. procera, N. brevidactyla, N. papillata, N. pseudohyalina, N. hyalina var. aberrans and Tolypella yunnanensis; while the third is Nitella globulifera Pal andN. japonica T. F. Alle     

Identification of pathogenic dematiaceous fungi and related taxa based on large subunit ribosomal DNA D1/D2 domain sequence analysis

The nucleotide sequences of the D1/D2 domains of large subunit (26S) ribosomal DNA for 76 strains of 46 species of pathogenic dematiaceous fungi and related taxa were determined. Intra-species sequence diversity of medically important dematiaceous fungi including Phialophora verrucosa, Fonsecaea pedrosoi, Fonsecaea compacta, Cladophialophora carrionii, Cladophialophora bantiana, Exophiala dermatitidis, Exophiala jeanselmei, Exophiala spinifera, Exophiala moniliae, and Hortaea werneckii were extremely small; as few as 0 changes were detected in C. bantiana, Fonsecaea and Exophiala species, 1 bp in C. carrionii and H. werneckii, and 2 bp in P. verrucosa. Inter-species nucleotide diversity between most species was higher. These data suggested that the D1/D2 domain is sufficiently variable for identification of pathogenic dematiaceous fungi and relevant species. The phylogenetic trees constructed from the sequence data revealed that most human pathogenic species formed a single cluster and that Cladosporium and Phialophora species were distributed polyphyletically into several clusters.