Search results for "Aquatic liverworts"
showing 7 items of 7 documents
Riella cossoniana Trab. (Riellaceae, Marchantiophyta) new to France
2014
Riella (Riellaceae, Sphaerocarpales) is a genus of aquatic liverworts with disjunct range in areas of Mediterranean-type climates. Riella has been traditionally subdivided into two subgenera, subgenus Riella, whose plants show smooth or papillose female involucres and Trabutiella, whose plants show winged female involucres. To date only three species of Riella are known in France, all belonging to subgenus Riella. During the course of a study of the plant diversity of temporary brackish ponds in the Camargue area (Southern France), soil sediments were collected from 10 localities and cultivated in the laboratory. From cultures of five of these localities emerged dioicous plants of Riella sh…
Taxonomic revision of Riella subgenus Trabutiella (Riellaceae, Sphaerocarpales)
2014
The genus Riella (Riellaceae, Sphaerocarpales) includes some 24 species of thalloid aquatic liverworts with unique morphological and ecological features among hepatics. These include the development of sporophytes enclosed within involucres and growing submerged in seasonal fresh or brackish water ponds. Riella subgenus Trabutiella includes species with winged involucres. Seven taxa have been described, however, four to five taxa have been recognized at a time depending on authors. In this study we have conducted a morphological revision of the species of this subgenus, based on 59 traits measured under light and Scanning Electron Microscopy analyses and that were the subject of statistical…
Rediscovery of Riella alatospora (Riellaceae, Sphaerocarpales), an aquatic, South African endemic liverwort previously known from a now largely trans…
2012
7 páginas, 4 figuras.
Riella heliospora (Riellaceae) a new monoicous species of Riella subgenus Trabutiella from California
2012
14 páginas, 8 figuras, 1 tabla.
Riella bialata Trab. (Riellaceae, Marchantiophyta): A new addition to the European liverwort flora
2013
[EN] Riella (Riellaceae, Sphaerocarpales) is a genus of aquatic liverworts with a disjunct worldwide distribution in areas of seasonal Mediterranean-type climates. Its centre of diversity is located in the Mediterranean basin, where about half the species number of the genus is concentrated. In the course of a worldwide revision of the genus Riella, plants from a monoicous species with wingless, not papillose and smooth involucres were found in two distant Iberian localities. These plants showed a geminate dorsal wing, unlike the single wing occurring in the remaining species of the genus. This character unambiguously assigns these populations to R. bialata, a species known to date from a s…
Advances in the knowledge of South African Riella (Sphaerocarpales) and a new endemic species, Riella trigonospora
2014
Cultures of soil sediments collected in June 2012 from saltpans and vleis from five South African localities have revealed two new, geographically distant, populations of the endemic Riella alatospora, confirmed the presence of Riella purpureospora from Blouvlei in the Cape Town area and uncovered a new endemic species, Riella trigonospora. The new species obtained from cultures from five sampled localities is described and illustrated. It is dioicous and characterised by acuminate to rostrate, papillose involucres and by a unique spore morphology. The spores are dark purple, as in R. purpureospora, and have an irregular discontinuous wing at the equatorial plane, which suggests a morpholog…
Study of a New Population of the Argentinian Endemic Species Riella choconensis Hässel (Riellaceae, Marchantiophyta) Reveals a Novel Anatomical Struc…
2019
A new population of the Argentinian endemic Riella choconensis Hässel (Riellaceae, Marchantiophyta) was discovered from a culture of sediments from the Laguna de los Juncos (Río Negro province, Argentina). This species was known previously from two nearby collections, made in 1984, in the type locality at the Ramos Mexía reservoir (Neuquén province) and was not recorded since. Fresh material from the new population enabled detailed morphological analyses, which are extensively described here, illustrated and compared to type material of the species. Based on the smooth female involucre, the species belongs to subgenus Riella Mont. However, cross-sections of this structure showed that R. cho…