Entity

Time filter

Source Type


Truong C.,Conservatoire et Jardin botaniques de la Ville de Geneva | Truong C.,Faculte Des Science Of Luniversite Of Geneva | Rodriguez J.M.,National University of Cordoba | Clerc P.,Conservatoire et Jardin botaniques de la Ville de Geneva | Clerc P.,Faculte Des Science Of Luniversite Of Geneva
Lichenologist | Year: 2013

Abstract The diversity of pendulous Usnea species in tropical South America (Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru and Venezuela) and the Galapagos Islands is discussed with reference to 23 species. Usnea crenulata Truong & Clerc is newly described. Usnea articulata, U. deformis, U. dimorpha, U. geissleriana, U. merrillii, U. perhispidella, U. sanctaeritae, U. subflammea and U. transitoria are newly reported for South America. Modern descriptions are provided for Usnea amabilis, U. arthroclada, U. dodgei, U. humboldtii and U. regia. We propose to reject the synonymy of U. hesperina with U. schadenbergiana, and the valid name for U. hesperina is therefore U. subgracilis. Distinct patterns of unidentified triterpenoids have been detected by thin-layer chromatography and are used to characterize several species within this group. The morphology, branch anatomy, chemistry, ecology and distribution of each species are given, together with an identification key. © British Lichen Society, 2013. Source


Truong C.,Faculte Des Science Of Luniversite Of Geneva | Clerc P.,Faculte Des Science Of Luniversite Of Geneva
Lichenologist | Year: 2013

Eumitrioid Usnea species are characterized by a tubular central axis throughout the entire thallus. Four species were identified in South America: Usnea baileyi is a (sub-) tropical species occurring both in continental South America and the Galapagos; U. perplectata has a scattered distribution worldwide and occurs in continental South America, mainly on the eastern range; U. flaveola and the newly described species U. subflaveola are both so far endemic to the Neotropical Andes. Distinct chemotypes, as well as anatomical characters, such as the thickness ratio of the medulla or the presence of medullar pigmentation, are diagnostic in delimiting these species. A detailed description of the species is provided together with an identification key. © 2013 British Lichen Society. Source


Truong C.,Conservatoire et Jardin botaniques de la Ville de Geneva | Truong C.,Faculte Des Science Of Luniversite Of Geneva | Bungartz F.,Charles Darwin Foundation | Clerc P.,Conservatoire et Jardin botaniques de la Ville de Geneva | Clerc P.,Faculte Des Science Of Luniversite Of Geneva
Bryologist | Year: 2011

Usnea species with a red-orange cortical or subcortical pigmentation were studied in the tropical Andes (Venezuela, Colombia, Ecuador, Peru and Bolivia) and the Galapagos Islands. Sixteen species are treated, 14 occurring in the Andes and six in the Galapagos. Usnea crocata, U. grandisora (endemic to the Galapagos), U. rubricornuta and U. subdasaea are newly described. Usnea dorogawensis, U. michauxii, U. subcornuta and U. subrubicunda are new to South America. Tri-terpenoids detected by thin layer chromatography play an important role in the taxonomy of this group of species. Several species were found both in the Andes and the Galapagos, and the diversity of species integrates elements from North America, tropical Africa, Macaronesia and even Asia. This emphasizes the importance of examining large geographic areas to better understand global distribution patterns in this cosmopolitan genus. © 2011 The American Bryological and Lichenological Society, Inc. Source

Discover hidden collaborations