Schoenoplectus × flevensis (S. lacustris × S. tabernaemontani, Cyperaceae) in Britain

Intermediates between Schoenoplectus lacustris and S. tabernaemontani have been recognised at least since the late 19th century and for much of that time, there has been speculation that such intermediates may involve hybridisation. In 2017 the hybrid status of a population growing in the South-Forty-foot Drain in Lincolnshire was confirmed using molecular tools. This article presents information on the hybrid, both from the Lincolnshire population and from the literature, as well as providing an indication of how hybrid populations might be recognised. The binomial Schoenoplectus × flevensis (D.Bakker) Lansdown & Rumsey is proposed for the hybrid.

The dynamics of overgrowing of spawning areas of Lake Pskov, using the example of Anokhovo Bay

The dynamics of overgrowing of spawning grounds in the southern area of Peipsi-Pihkva Lake complex is considered, based on 28 years of observations from Anokhovo Bay. The history of the study of the water area is analyzed in detail, the species and syntaxonomic composition of plant associations in the littoral areas of the bay is described, and the dominant species are established. Over the entire observation period, the total number of macrophyte species increased by almost 2.5 times, and the number of plant associations increased approximately twofold. The area of the bay overgrown with macrophytes increased by 9.5%, with a simultaneous increase in the overgrowth density. The dominant species are common reed Phragmites australis, lakeshore bulrush Schoenoplectus lacustris, and yellow water-lily Nuphar lutea.

Microscopic fungi on Schoenoplectus lacustris in Płociczno and Płociowe lakes in Drawa National Park (northwest Poland)

In the period 2009–2011, the micromycetes causing symptoms on the leaves of <em>Schoenoplectus lacustris</em> (SL) from Płociczno and Płociowe lakes in Drawa National Park (DNP) were investigated. A total of 39 taxa of microscopic fungi and chromistan fungi were found. The taxonomic structure of the mycobiota was dominated by anamorphs of Ascomycota. In each year of the study, the SL fungal species richness was higher in Płociowe Lake than in Płociczno Lake. In all the years of study in both lakes, the fungal community on SL was composed of the following six dominant species: <em>Alternaria alternata</em>, <em>Cladosporium herbarum</em>, <em>Fusarium incarnatum</em>, <em>F. sacchari</em>, <em>Gibberella avenacea</em>, and <em>Pleospora scirpicola</em>. The species occurring exclusively in Płociczno Lake were <em>Papulaspora immersa</em>, <em>Puccinia scirpi</em>, and <em>Trichothecium roseum</em>, and those found only in Płociowe Lake were <em>Acremoniella atra</em>, <em>Alternaria atra</em>, <em>Aspergillus niger</em>, <em>A. versicolor</em>, <em>Fusarium oxysporum</em>, <em>Gonatobotrys simplex</em>, <em>Massariosphaeria scirpina</em>, <em>Microascus brevicaulis</em>, <em>Penicillium chrysogenum</em>, and <em>Stagonospora aquatica</em>. Only one confirmation of the occurrence of <em>Puccinia scirpi</em> and the lack of other specialized obligate parasites indicate the good health of SL in DNP. The facultative parasites, inter alia, <em>Boeremia exigua</em>, <em>Chaetomium globosum</em>, <em>Fusarium culmorum</em>, <em>F. incarnatum</em>, <em>F. sacchari</em>, <em>Gibberella avenacea</em>, and <em>Stagonospora aquatica</em> that are present on plants as part of the natural process of apoptosis may influence the health of SL.

Peculiarities of Epiphyton Algal Communities Formation on Different Macrophyte Species

Karosienė J., Kasperovičienė J., 2012: Peculiarities of epiphyton algal communities formation on different macrophyte species [Skirtingų makrofitų rūšių epifitono dumblių bendrijų formavimosi ypatumai]. - Bot. Lith., 18(2): 154-163. The epiphyton on different aquatic vegetation represented by emerged macrophytes (Phragmites australis, Equisetum fluviatile, Schoenoplectus lacustris), floating-leaved plants (Nuphar luteum) and submerged macrophytes (Potamogeton perfoliatus, Chara rudis) was studied in two meso- and mesoeutrophic lakes. The morphological characteristics, physiological and synecological peculiarities of plant host had more effect on epiphyton algae abundance and biomass than species richness. The highest densities of algae were associated with helophytes Phragmites australis, Equisetum fluviatile, the lowest was recorded on Schoenoplectus lacustris and laminae of Nuphar luteum. Loosely attached diatoms prevailed on helophytes, adnate species on Nuphar luteum laminae. Cyanobacteria and green algae were more abundant on Nuphar luteum laminae and Potamogeton perfoliatus.

Potential Impact of Climate Change on Aquatic Vegetation of River Salaca, Latvia

Potential Impact of Climate Change on Aquatic Vegetation of River Salaca, Latvia Species diversity and cover of aquatic macrophytes were investigated in the River Salaca in 2007. In total 24 different taxa were found. Schoenoplectus lacustris was the dominant species, Sagittaria sagittifolia, Nuphar lutea, Nymphaea candida, Butomus umbellatus and different Potamogeton species were frequent. Cover of macrophytes varied in the river between 10-90%, maximum in-stream cover reached in rapidly flowing sites. Comparison of total cover of macrophytes in 1986 and 2002 surveys of several stretches was done. Causes for the changes are discussed. The increasing growth of aquatic vegetation in the River Salaca have been related to climatic factors—higher mean annual air temperatures, earlier springs and decrease in the period of ice cover in winter.

Hypohelion scirpinum. [Descriptions of Fungi and Bacteria].

A description is provided for Hypohelion scirpinum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Hypohelion scirpinum usually occurs on dead fallen stems and leaves of Schoenoplectus lacustris. Virtually nothing is known about the ecology of this fungus, except for Ingold's observation that its life cycle is entirely aquatic. It seems likely however that, like many other members of the Rhytismataceae, the fungus colonizes the living plant, then fruits on those leaves and stems after they have died. HOSTS: Arundinaria macrosperma (stem), Plantae gen. indet. (leaf), Schoenoplectus lacustris (stem, dead floating stem), Scirpus lacustris var. occidentalis (stem), S. validus (stem), Scirpus sp. (stem). Almost all records are from Schoenoplectus lacustris, many of the others are misidentifications or synonyms for this plant. The record on Arundinaria is questionable. GEOGRAPHICAL DISTRIBUTION: Belgium, Canada (Saskatchewan), France, Germany, Hungary, Italy, Latvia, Russia (Tver Oblast), Sweden, UK (England), Ukraine, USA (Dakota, Mississippi). A temperate northern hemisphere species of low altitude, not very acidic wetlands and slow flowing rivers. Rather infrequently recorded, with numbers of records declining, and some unsuccessful searches for this fungus in apparently suitable habitats in recent years. TRANSMISSION: By air-borne ascospores in humid conditions.