During our study of the biodiversity of the Guianas and the preparation of the flora of this region, we discovered that the I. Valdespino’s monograph of the genus Selaginella subgen. Heterostachys was never published. Two taxa, S. gynostachya and S. karowtipuensis, presented in this monograph and new to the Guianas, are published herein.
Trichomanes L. sensu lato (s.l.), is a large group of Hymenophyllaceae to which ca. 250 species are attributed, distributed from the tropics to temperate regions around the world,. Their life forms and morphology are more diversified than those of the other large filmy-fern genus Hymenophyllum. Phylogenetic analyses were performed based on the rbcL sequences of 81 Trichomanes taxa, covering most of the major groups within the genus, in addition to morphological, anatomical and cytological investigations, that offer a number of insights concerning evolution of the genus. Eight robustly supported clades are recognized within Trichomanes, while some traditional trichomanoid taxa (e.g., Pleuromanes) are transferred to the Hymenophyllum clade.
The genetic relatedness of individuals can give a population finer scale spatial pedigree structure. The relation of genetic similarity and spatial distance refers to the dispersal characters and reproductive relations existing among individuals. Our main purpose here was to obtain information on the genetic spatial pattern before a more profound spatial autocorrelation analysis of Asplenium ceterach individuals. Three physically isolated subpopulation patches of the tetraploid A. ceterach subs. ceterach were identified on the southern rocky faces of the St. György Hill in Hungary. The genetic properties were scored and cluster analysis, UPGMA, was carried out in three steps using progressively larger samples: 42, 85 and 320 individuals were chosen. Cluster analysis revealed a minimum of 70% genetic similarities among individuals indicating intensive gene flow between subpopulations, but there was also detectable correspondence between individual genetic similarities and spatial position.
The Global Strategy for Plant Conservation (GSPC) sets out a series of activities with targets intended to halt the decline in plant biodiversity by 2010. This article examines the current state of knowledge concerning the conservation status of ferns in relation to Target 2 of the GSPC. The change in criteria used by the World Conservation Union (IUCN) for assessing conservation status has led to data generated prior to 1997 being marginalised. The latest information, using the revised criteria and published in 2003, refers to a smaller number of pteridophyte species, with only ten species being common to both the 1997 and 2003 assessments. There is an urgent need to capture the knowledge that pteridologists and other specialists undoubtedly have, relating to the conservation status of ferns and fern allies, and to incorporate this into Red Data Lists to provide firmer foundations for the GSPC.