Botanica Lithuanica, Volume 12, Number 2

2006 m.

Bunias orientalis, the native of the European part of Russia, the Caucasus, western Siberia, and now also common in Central and some other parts of northern and western Europe, is among the most widespread alien species of Latvia. Studies on the Bunias orientalis, including the history of its advent, current patterns of distribution, migration routes, and tendencies, reveal significant regularities responsible for the spread of invasive species to new regions, which permit certain generalizations relevant also for other species. First recorded in Latvia in 1803, today the number of registered Bunias orientalis localities is 337 with the highest increase in the recent period. The distribution of this species, using the standard grid of 10 × 10 km for mapping, has been intensively studied in the last decades, and the most representative data are now available. Bunias orientalis is found mostly along the highways, railway lines, and in heavily disturbed habitats; to a lesser extent in grasslands, fallow lands, fields, orchards, on the riversides, forest edges, and others habitats. Most of the localities are in eastern Latvia, central part of eastern Latvia, in the vicinity of some biggest cities mostly in eastern Latvia, and the country’s capital; the species is less common on the seacoast, and even less in western Latvia. The lowest concentration of localities is in the central part of Latvia and the central part of western Latvia. Mapping of the registered Bunias orientalis localities in a historical sequence helps track down its migration routes in the east-west direction, which for the most part follow the highways, railways, and rivers. Limy soils and continental climatic conditions greatly facilitate the spread and establishment of Bunias orientalis in new localities. It is concluded that this alien species emerges mainly next to the arterial roads and rivers and migrates along them. In this respect the role of farming and gardening is less significant.

Keywords: Bunias orientalis, alien species, distribution, migration routes, Latvia.

This paper presents a comparative study of the anatomical structure of stem, leaf, and root of three species of Clematis L. (Ranunculaceae). Anatomical characteristics such as presence of inner peridermal ring in stem, supporting tissue on cortex, number of vascular bundles, the upper or lower positions of stomata were determined.

Keywords: Clematis, anatomy, Turkey.

A study was carried out to identify species of forest trees that are preferentially extracted for timber by assessing their disappearance from the forest reserve, its effects on the flora and structure of the vegetation and their presence at the sawmills in Isokan Local Government area of southwestern Nigeria. Three 25 × 25 m sample plots in Ago-Owu forest reserve and six sawmills in Isokan Local Government area, Nigeria, were selected. Results showed that the density of non-timber species per hectare was higher than density of the timber species in all three forest plots. The flora composition of the study forest plots and the study of sawmills fields revealed the most commonly logged timber species. The study also revealed that logging activities have resulted in the loss of important timber tree species in the study forest.

Keywords: vegetation structure, logging, forest reserve, sawmills, southwestern Nigeria.

Notes on the occurrence of 12 species of straminipilous fungi belonging to the Saprolegnia Nees genus in Lithuania are presented. All species are briefly described and illustrated; the taxonomical position of some of them is discussed. Saprolegnia anisospora, S. furcata, S. glomerata, S. latvica, S. parasitica, and S. terrestris are reported for the first time in Lithuania.

Keywords: straminipilous fungi, Saprolegnia, species diversity, Lithuania.

The paper presents the results of lichenological investigations during the 16th Symposium of Mycologists and Lichenologists of Baltic States. Fifty three species were recorded; 27 of them are new to Latvia. New lichens are: Absconditella lignicola, Bacidina chloroticula, Biatora helvola, B. ocelliformis, Cladonia norvegica, Collema limosum, Lecanora thysanophora, Lecidea nylanderi, Leptogium biatorinum, Micarea misella, Moelleropsis nebulosa, Pertusaria pupillaris, Placynthiella dasaea, Sarcosagium campestre, Thelocarpon intermediellum, Trapeliopsis glaucolepidea, Usnea substerilis, Verrucaria aquatilis, V. bryoctona, V. dolosa, V. praetermissa; new lichenicolous fungi are: Biatoropsis usnearum, Lichenoconium erodens, Nectriopsis lecanodes, Pronectria xanthoriae, Tremella cetrariicola; new saprobic fungus: Mycomicrothelia wallrothii. One species, Moelleropsis nebulosa, is also the first record for the Baltic countries.

Keywords: lichens, lichenicolous fungi, Latvia.

A phytoplasma was detected in tall fescue (Festuca arundinacea Schreb.) exhibiting symptoms of general yellowing, stunting, proliferation of stems, sterility, and withering of spikes. Diseased plants were collected at the Plant Breeding Centre of the Lithuanian Institute of Agriculture in the selection-experimental fields. The presence of phytoplasma in diseased tall fescue was demonstrated using polymerase chain reaction (PCR) assays. The amplification yielded 1.8 kb (primer pair P1/P7) and 1.2 kb (primer pair R16F2n/R16R2) PCR products using direct and nested-PCRs, respectively. Restriction fragment length polymorphism (RFLP) analysis of amplified 16S rDNA indicated that diseased tall fescues were infected by phytoplasma belonging to the group 16SrI (aster yellows, AY), subgroup 16SrI-C, which type strain is clover phyllody (CPh). The phytoplasma strain detected in tall fescue was named fescue yellows (FesY) phytoplasma. This is the first report of phytoplasma belonging to 16SrI-C subgroup identified in tall fescue plants.

Keywords: Festuca arundinacea, phytoplasma, PCR, RFLP, 16S rRNA gene.

Erysiphe azaleae (º Microsphaera azaleae) on Rhododendron is reported for the first time from Lithuania. The morphological features of this fungus are described, illustrated, and discussed.

Keywords: powdery mildews, Rhododendron, Lithuania.

The paper presents new data on the rare anamorphic fungi in Europe and Lithuania: Eriospora leucostoma, Scolecosporiella typhae, and Stictosepta cupularis. Descriptions and illustrations of the species are provided.

Keywords: anamorphic fungi, Eriospora leucostoma, Scolecosporiella typhae, Stictocepta cupularis.