A revision of the genus Potamium (Musci: Sematophyllaceae).

The neotropical genus Potamium as described by Mitten (1869) included species that had little more in common than a growth form adapted to a semi-aquatic habitat. Brotherus divided the genus in section Eu-Potamium and section Potamiopsis, based on peristome characters. This study shows that all species of section Eu-Potamium belong to Sematophyllum, including P. lonchophyllum which was designated as lectotype of Potamium by Buck (1990). In section Potamiopsis two species are recognized: P. vulpinum (Mont.) Mitt. (syn. nov.: Sematophyllum maguireorum Buck) and P. deceptivum Mitt. (syn. nov.: P. leucodontaceum (C.Müll.) Broth., Meiothecium negrense Mitt. and Maguireella vulpina (Mont.) Buck). The genus Potamium is characterized by capsules with an endostome consisting of a low basal membrane and filiform segments, which are often reduced in P. deceptivum. P. vulpinum is designated as lectotype of Potamium and the lectotypification of Buck is rejected. Descriptions, illustrations and a key are provided to the species of Potamium and allied semiaquatic taxa of Sematophyllum

A catalogue of the bryophytes of the Guianas : 2., Musci

This catalogue provides an annotated listing of the mosses (MUSCI) reported from the Guianas (Guyana, Surinam, French Guiana), based on work on the Moss Flora of Suriname, which is now nearing completion. In total 238 species in 90 genera are listed. A list of synonyms (including 10 new ones) and a systematic arrangement of the genera and families are also provided. The following new combinations are proposed: Callicostella guatemalensis (Bartr.), Sematophyllum lonchophyllum (Mont.), Sematophyllum pacimoniense (Mitt.) and Trichosteleum intricatum (Thér.)

Results of a botanical expedition to mount Roraima, Guyana. I. Bryophytes

A bryological inventory of the Upper Mazaruni District, Guyana (former British Guiana) yielded almost three hundred species, including 2 genera and 11 species new to science and 130 species new to the Guianas. The densely forested and very humid north slope of Mount Roraima (500-2300 m.) proved to be the richest area for bryophytes and most of the novelties were found there. The present paper provides an enumeration of the species collected with a brief characterization of their habitat. The following species are described as new: Haesselia acuminata Gradst., Plagiochila gymnocalyx Inoue, Radula gradsteinii Yamada, Radula guyanensis Yamada, Radula mazarunensis Yamada and Stenorrhipis grollei Gradst. Anastrophyllum subg. Vanaea Inoue & Gradst. from Mount Roraima is elevated to generic rank

Musgos (Bryophita) do nordeste Paranaense, Brasil -1. Zona Bragantina, microrregião do Salgado e município de Viseu Mosses (Bryophyta) of northeast Pará, Brazil -1. Zona Bragantina Salgado microregion and Viseu municipality

Neste trabalho foram inventariadas as espécies de musgos que ocorrem nos diferentes tipos de vegetação dos municípios da Zona Bragantina, da Microrregião do Salgado e município de Viseu, todos localizados no Nordeste Paraense. Coletaram-se 632 amostras, que resultaram em 60 espécies e uma variedade, distribuídas em 30 gêneros e 16 famílias. Sematophyllaceae, Calymperaceae e Leucobryaceae destacaram-se em diversidade de espécies e número de ocorrências. Sematophyllum subsimplex (Hedw.) Mitt. e Calymperes lonchophyllum Schwaegr. são as espécies mais abundantes. Os resultados referentes à Microrregião do Salgado são comparados aos encontrados na Zona Bragantina e município de Viseu. Ocorre maior diversidade nas matas primárias, indicando que a substituição delas por vegetação secundária resulta no empobrecimento da diversidade das espécies de musgos.<br>This paper is an inventory of moss species occuring in diferent types of vegetation in the Zona Bragantina, Salgado microregion and Viseu municipalities, all located in the northeast of Pará. The results found 60 species and one variety in 632 moss samples, distributed in 30 genera and 16 families. Sematophyllaceae, Calymperaceae e Leucobryaceae were prominent in diversity of species and number of occurrencies. Sematophyllum subsimplex (Hedw.) Mitt. and Calymperes lonchophyllum Schwaegr. are the most abundant species. The results found at Salgado Microregion were compared to the results found at Zona Bragantina and Viseu municipalities. There is a higher diversity in primary vegetation, indicating that the replacement by the secondary vegetation results in the impoverishment of moss species diversity