The coralline red alga Mesophyllum (Hapalidiaceae) is recorded for the first time from the Gulf of Trieste (Northern Adriatic Sea) and gametangial plants of M. macroblastum are recorded for the first time from the Mediterranean Sea. A morphological-anatomical account is provided, including comparisons with specimens from the western coast of Italy and with published data. Distribution and habitat information, comparison with Mediterranean species of Mesophyllum, and a dichotomous key to Mediterranean species are included along with brief comments on other species in the genus known to produce volcano-like tetrasporangial conceptacles.

During the last ten years, water blooms of Aphanizomenon have been observed in aquatic environments of the subtropical region of Argentina. These blooms have been observed to present taxonomic characteristics similar to those of A. platensis, a species originally described by Seckt in the Delta of Paraná River, a region of temperate climate, in 1921. Water blooms of Aphanizomenon have been observed in aquatic environments of Corrientes Province, a region of Argentina with subtropical climate, during the last ten years. Considering these aspects, we analysed the morphological variation of A. platensis in two water bodies located in the northwest of Corrientes province (27° 29′ S; 58° 45′ W). Our description includes characteristics of the akinetes, which were not originally found by Seckt. The revision of this taxon is important because the species of Aphanizomenon are potentially toxic, invasive, and bloom formers. Our study confirms the existence of this morphospecies almost 90 years after it was first described. We further describe the whole species and extend its distribution to the subtropical region, in environments related to the hydrographic net of the Rio de la Plata Basin. Taking into account the diacritic characters analyzed, we may conclude that A. platensis is a polymorphic species with highly variable cell dimensions, probably due to variations in the environmental conditions.

The number of Closterium species known from the Burkina Faso is small. The present study aims to contribute to the knowledge of species of this genus in Burkina Faso by means of an investigation of temporary ponds. The study of Closterium in ponds was conducted in the central and the eastern parts of the country, during the rainy seasons of 2007 and 2008. Samples were collected and preserved with formalin. Aliquots of the samples were examined and illustrations made with a light microscope equipped with a drawing tube and a camera. Identifications of species were made with the use of standard works. In total, twenty-six taxa of Closterium were identified and described. Among them, twenty-four have already been reported from Africa and nineteen are cosmopolitan. Eighteen species (62%) are new for the country. The number of species reported shows that Closterium could be considered as a diverse genus in temporary ponds. Some species are either neutrophiles or alkaliphiles but many of them are neutrophiles as well as alkaliphiles.

Fifty-nine species of marine benthic algae are reported for the first time from the coral reefs of isolated Swains Island, American Samoa, based on collections made during February 2002, 2004, 2006, and March 2008 under the auspices of the U.S. National Oceanic and Atmospheric Administration. The collections include 4 species of blue-green algae (cyanobacteria), 38 species of red algae, 3 species of brown algae and 14 species of green algae. Based on their frequency of occurrence at different stations during the 4 cruises, Rhipilia geppiorum and Microdictyon umbilicatum were considered the most widely distributed species during the months of February and March. Twenty-eight species represent new records for the Samoan Archipelago (American Samoa and Samoa).

Choreonema thuretii and Pneophyllum confervicola, two cosmopolitan species, are here recorded for the first time for the Azores. They were found during an investigation of intertidal communities in Pico Island (Azores) in the summer of 2007. Both species were found hosted in Jania rubens specimens, C. thuretii as a semi-endophytic parasite, P. confervicola as an epiphyte. They are present on other archipelagos from Macaronesia (Madeira and Canary Islands). It is likely that they have been overlooked in the Azores due to their small size and parasitic/epiphytic habit. A morphological and anatomical account is provided for both species, and it is hoped that this additional observations provided herein will alert field surveyors for their presence.

A modern station of Lychnothamnus barbatus (Charophyceae) in Central Italy: the Lake of Martignano (Lazio). The charophyte Lychnothamnus barbatus (Meyen) Leonh., in decline worldwide, is recorded in a new locality in Central Italy: the Lake of Martignano (Latium). It occurs with low coverage in a phytocoenose where Ceratophyllum demersum L. is dominant.