45 research outputs found
niederländischer Dichter und Politiker (1767-1840); Rede anläßlich der Enthüllung einer Gedenktafel am 2.7.2006, Weenderstraße 19
No full textDiscovery of the African liverwort genus Cephalojonesia (Cephaloziellaceae) in Mexico
No full textThe monospecific liverwort genus Cephalojonesia (Cephaloziellaceae), known from a few localities in Central Africa, is newly reported from Mexico. Based on characters of the female involucre the Mexican material is described as a new subspecies, C. incuba subsp. mexicana Burghardt, Gradst. & Vana. The new subspecies is illustrated and discussed, and an updated key to the genera of Cephaloziellaceae of tropical America is provided
Discovery of the African liverwort genus Cephalojonesia (Cephaloziellaceae) in Mexico
No full textThe monospecific liverwort genus Cephalojonesia (Cephaloziellaceae), known from a few localities in Central Africa, is newly reported from Mexico. Based on characters of the female involucre the Mexican material is described as a new subspecies, C. incuba subsp. mexicana Burghardt, Gradst. & Vana. The new subspecies is illustrated and discussed, and an updated key to the genera of Cephaloziellaceae of tropical America is provided
Threatened bryophytes of the neotropical rain forest : a status report
No full textTropical deforestation, inevitably, leads to the local loss of bryophyte species. Recent studies show that the degree of species loss may vary considerably and depends on the scale or amount of habitat change that has occurred. Predictably, the shade epiphytes are most seriously affected by disturbance. An estimated 10% of the bryophyte species of neotropical rain forests are under threat. Based on data from recent monographs, a first list of 19 endangered and 27 rare species of these forests is presented. Critical areas for threatened species include Costa Rica and Panama, the Greater Antilles, the Chocó, southeastern Brazil, and parts of Amazonia. Protection of as much as possible of the remaining natural rain forest area seems the best approach to the conservation of the tropical bryophyte flora
A Taxonomic Monograph of the Genus Acrolejeunea (Hepaticae) with an Arrangement of the Genera of Ptychanthoideae (Studies on Lejeuneaceae subfam. Ptychanthoideae III)
No full textThe present study was initiated a few years ago by Dr. R. Grolle (Jena) who discovered that Acrolejeunea (Spruce) Schiffn. was probably the correct name for a tropical liverwort genus to which in this century the name Ptychocoleus Trev. was applied. Since replacing the name Ptychocoleus by Acrolejeunea would necessitate a considerable number of nomenclatural changes, I was asked to reexamine the taxonomy of the group.
I soon found that Ptychocoleus as traditionally understood is heterogeneous and consists of two well-defined genera: Acrolejeunea (Spruce) Schiffn. and Schiffneriolejeunea Verd. (Gradstein 1974a). In order to determine their taxonomic affinities, I decided to review the generic subdivision of the subfamily Ptychanthoideae (Lejeuneaceae) to which they belong. The present work comprises the taxonomic monograph of Acrolejeunea and the review of the subfamily. The monograph of Schiffneriolejeunea will be published separately
Diversity and distribution of Asian Lejeuneaceae subfamily Ptychanthoideae
No full textA synopsis is provided of 88 species in 17 genera currently recognized in Lejeuneaceae subfamily Ptychanthoideae sensu lato (including Nipponolejeunea) of Asia. Taxonomic novelties include Thysananthus flavescens (Hatt.) comb. nov. (for Mastigolejeunea flavescens (Hatt.) Mizut.), Spruceanthus macrostipulus (Steph.) comb. nov. (for Archilejeunea macrostipula (Steph.) Verd.) and the reduction of Platylejeunea Mizut. to synonymy under Lopholejeunea
Results of a botanical expedition to mount Roraima, Guyana. I. Bryophytes
No full textA 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
On the occurrence of bryophytes and macrolichens in different lowland rain forest types at Mabura Hill, Guyana
No full textA floristic and ecological study of bryophytes and macrolichens in different lowland rain forest types around Mabura Hill, Guyana, South America, yielded 170 species: 52 mosses, 82 liverworts and 36 macrolichens. Lejeuneaceae account for about 30% of the species and are the dominant cryptogamic family of the lowland rain forest. Special attention was paid to the flora of the forest canopy, by using mountaineering techniques. It appeared that 50% of the bryophyte species and 86% of the macrolichens occurred exclusively in the canopy. Dry evergreen 'walaba' forest on white sand is particularly rich in lichens whereas the more humid 'mixed' forest on loamy soil is characterized by a rather rich liverwort flora. More species are exclusive to the mixed forest than to dry evergreen forest due to the 'canopy effect', i.e. the occurrence of xerophytic species in the outer canopy of both dry and humid forests. Furthermore, canopy species have wider vertical distributions on trees in the dry evergreen forest than in the mixed forest, due to the more open canopy foliage of the dry evergreen forest
Epiphytic bryophytes of Monteverde, Costa Rica
No full textA survey of the literature and collections in the Monteverde Cloud Forest Preserve and adjacent pastureland yielded a total of 198 epiphytic bryophyte taxa (120 species of hepatics in 50 genera, 77 species of moss in 48 genera, and 1 hornwort): 178 in the primary forest, 63 in the secondary forest, and 84 in the pastureland
