PendulousUsneaspecies (Parmeliaceae, lichenized Ascomycota) in tropical South America and the Galapagos

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.

From GenBank to GBIF: Phylogeny-Based Predictive Niche Modeling Tests Accuracy of Taxonomic Identifications in Large Occurrence Data Repositories

“…This finding indicates that tropical and Southern Hemisphere reports of this species are incorrect, which was subsequently tested by analyzing monographic revisions (including unpublished data) of the genus Usnea in the areas where the outliers occurred, in particular Mexico, Costa Rica, Colombia, and Australia (see Discussion ). All revisions confirm the absence of Usnea longissima in these regions, highlighting common misidentifications with similarly long, pendulous species which, however, differ in branching pattern, surface morphology, internal anatomy, and secondary chemistry [ 15 , 19 – 21 ; M. Herrera-Campos, P. Clerc, pers. comm.…”

“…longissima was not confirmed, whereas the report from Colombia represents a previously unrecognized taxon, U . crenulata Truong & P. Clerc [ 21 ]. Other lichens often mistaken for U .…”

“…Molecular phylogenetic revision of pendulous species of Usnea from South America further confirmed the absence of U . longissima from the continent [ 21 ]. Taxonomic revision of Usnea in Australasia [ 19 – 20 ] also demonstrated the absence of U .…”

The Use of Anisaldehyde Sulfuric Acid as an Alternative Spray Reagent in TLC Analysis Reveals Three Classes of Compounds in the Genus <em>Usnea</em> Adans. (Parmeliaceae, lichenized Ascomycota)

“…Prior to this study, several patterns of substances considered as being triterpenes were detected in Neotropical Usnea species [14] especially specimens showing no reactions with the traditional reagents (K, C, and P) used in lichenology. Our study, however, shows that among these suspected triterpenes, carbohydrates and steroids are also present and that they are even relatively frequent among the tested species.…”

“…Their presence in the genus Usnea was mentioned in several systematics studies [10][11][12][13]. More recently, [14] detected distinct patterns of terpenoids/steroids in Neotropical species of Usnea, highlighting their importance for species identification in this genus. Despite being frequently mentioned in the literature, terpenoids and steroids in the lichen genus Usnea still remain poorly understood, and their presence is for instance not mentioned by Elix (2014).…”