Glyceria striata (Lam.) Hitchc., a species native to North America, was found as an alien species on several localities in the Hostýnské vrchy Mts (eastern Moravia). It grows there on disturbed sites in artificial, usually spruce and alder woods at an altitude of 340–550 m a.s.l. The way of introduction of G. striata to this area is uncertain. However, it is present as an alien in many European countries. A detailed synonymy and description of species is given. Taxonomy and systematics are shortly discussed and determination key within the Czech species of the genus Glyceria is also given. Notes on the distribution and the history of naturalization of the species in Europe as well as notes on its ecology are included.
Perennial grasses belonging to the genus Molinia are widespread in most of Europe and consist of a polyploid complex of closely related taxa with a confusing taxonomy. Based on extensive sampling at 241 localities in Europe, four cytotypes were identified based on chromosome counts and results of flow cytometry: tetraploids (2n = 36), hexaploids (2n = 54), octoploids (2n = 72) and dodecaploids (2n = 108). While tetra- and dodecaploids were commonly recorded, octoploids were less common and only two hexaploid individuals were identified. Previously reported decaploid counts (2n = 90) from central Europe are probably erroneous and refer to 2n = 108. The tetraploid cytotype is distributed throughout Europe and broadly sympatric with other cytotypes. Octo- and dodecaploids were spatially separated with dodecaploids occurring in the western, central and south-central part of Europe and octoploids in the east-central and southeastern part of Europe. All quantitative characters measured (lengths of lemmas, anthers, caryopses and stomata, lengths of the longest hair on the callus and diameter of the culm below the panicle) showed a linear trend across ploidy levels. Tetra-, octo- and dodecaploid cytotypes formed almost non-overlapping groupings in principal component and discriminant analyses of morphological characters. The following taxonomic concept of this complex is proposed: Molinia caerulea (L.) Moench is a predominantly tetraploid taxon incorporating very rarely reported hexaploid and perhaps also diploid plants; higher cytotypes (2n = 8x, 12x) are considered to be M. arundinacea Schrank, consisting of two subspecies: a dodecaploid subspecies occurring in the southern and western part of central Europe and the octoploid Molinia arundinacea subsp. freyi Dančák in east-central and southeastern Europe.
Forest dynamics, taxonomic diversity and synchronization of flowering are important ecological aspects of woody species of tropical forests in Borneo. Repeated measurements on permanent plots show that forest dynamics are driven by gap formation. Attempts have been made to explain high tropical diversity by a number of theories, ranging from the ecological equitability of species to narrow niche specialization. Finally, the conspicuous flowering synchronicity, principally of three species of the family Dipterocarpaceae, may be explained as a reaction on predation in regeneration phase. This phenomenon is triggered by climatic fluctuations connected to the El Nino-Southern Oscillation.