Attila Mesterházy

Alien aquatic vascular plants in Hungary (Pannonian ecoregion): Historical aspects, data set and trends

Estimating the extent of biological invasions is critical in predicting the effect of exotic species. We investigated the occurrence and number of alien freshwater plants and give information on the composition of alien aquatic flora, their trend in time, invasion pathway, and their invasive character.

Flood induced phenotypic plasticity in amphibious genus Elatine (Elatinaceae)

Vegetative characters are widely used in the taxonomy of the amphibious genus Elatine L. However, these usually show great variation not just between species but between their aquatic and terrestrial forms. In the present study we examine the variation of seed and vegetative characters in nine Elatine species (E. brachysperma, E. californica, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma and E. triandra) to reveal the extension of plasticity induced by the amphibious environment, and to test character reliability for species identification. Cultivated plant clones were kept under controlled conditions exposed to either aquatic or terrestrial environmental conditions. Six vegetative characters (length of stem, length of internodium, length of lamina, width of lamina, length of petioles, length of pedicel) and four seed characters (curvature, number of pits / lateral row, 1st and 2nd dimension) were measured on 50 fruiting stems of the aquatic and on 50 stems of the terrestrial form of the same clone. MDA, NPMANOVA Random Forest classification and cluster analysis were used to unravel the morphological differences between aquatic and terrestrial forms. The results of MDA cross-validated and Random Forest classification clearly indicated that only seed traits are stable within species (i.e., different forms of the same species keep similar morphology). Consequently, only seed morphology is valuable for taxonomic purposes since vegetative traits are highly influenced by environmental factors.

Revision of small ephemeral species of Eriocaulon (Eriocaulaceae) in West Africa with long involucral bracts

SummaryThe eight species of small ephemeral Eriocaulon known from West Africa with long involucral bracts are described and discussed. Three new species are included: E. cryptocephalum from Guinea (Conakry) and Sierra Leone, E. tingilomum from Sierra Leone and Ivory Coast and E. porembskii from Ivory Coast to Nigeria. A determination key to the eight included species is provided.

Cyperus glaber L. (Cyperaceae), an enigmatic species “new” to Spain

For the first time, Cyperus glaber L. is reported from Spain (Moral de Calatrava, province of Ciudad Real). The plants were previously erroneously ascribed to both Cyperus bellus Kunth and Cyperus rubicundus Vahl. Distinguishing features for these species are compared and some notes on residence status, ecology and habitat of Cyperus glaber in Spain are provided.

Growth‐form and spatiality driving the functional difference of native and alien aquatic plants in Europe

Abstract Trait‐based approaches are widely used in community ecology and invasion biology to unravel underlying mechanisms of vegetation dynamics. Although fundamental trade‐offs between specific traits and invasibility are well described among terrestrial plants, little is known about their role and function in aquatic plant species. In this study, we examine the functional differences of aquatic alien and native plants stating that alien and native species differ in selected leaf traits. Our investigation is based on 60 taxa (21 alien and 39 native) collected from 22 freshwater units of Hungarian and Italian lowlands and highlands. Linear mixed models were used to investigate the effects of nativeness on four fundamental traits (leaf area, leaf dry matter content, specific leaf area, and leaf nitrogen content), while the influence of growth‐form, altitude, and site were employed simultaneously. We found significantly higher values of leaf areas and significantly lower values of specific leaf areas for alien species if growth‐form was included in the model as an additional predictor.We showed that the trait‐based approach of autochthony can apply to aquatic environments similar to terrestrial ones, and leaf traits have relevance in explaining aquatic plant ecology whether traits are combined with growth‐forms as a fixed factor. Our results confirm the importance of traits related to competitive ability in the process of aquatic plant invasions. Alien aquatic plants can be characterized as species producing soft leaves faster. We argue that the functional traits of alien aquatic plants are strongly growth‐form dependent. Using the trait‐based approach, we found reliable characteristics of aquatic plants related to species invasions, which might be used, for example, in conservation management.

Mapania jongkindii (Cyperaceae), a new species from Liberia

SummaryA new species of Mapania, M. jongkindii is described and illustrated from the Nimba Mts, Liberia. It is separated from the related species, M. baldwinii and M. linderi, by characteristics of both leaf and fruit. Confirmation of this separation and the phylogenetic position of M. jongkindii was determined by phylogenetic analyses of DNA sequences from nuclear ribosomal Internal Transcribed Spacer and two chloroplast regions (rpoB and trnL-F IGS).