Tropical and Subtropical Lichens: Diversity and Floristics
Lumbsch, H. Thorsten , Luecking, Robert , Mangold, A. , Rivas-Plata, Eimy , Schmitt, Imke .
Tropical Thelotremataceae: Systematics and Molecular Analyses.
Thelotremataceae is a family of predominantly tropical lichens that has been poorly known, at the species level and the phylogenetic placement has been unclear. Within the last five years, a project has focused on these crustose lichens. Phylogenetic studies based on molecular data sets could show that the family is not a monophyletic group, but nested within Graphidaceae, another family of mostly tropical crustose lichens. Taxa previously placed in Thelotremataceae, mostly fall into two distinct clades: the Thelotrema clade with species having lateral paraphyses and the Ocellularia clade with often carbonized apothecial margins. The two families Graphidaceae and Thelotremataceae were mainly distinguished based on their ascoma morphology, which was shown to be of minor taxonomic importance. Consequently, the two families were merged with Graphidaceae being the older name for the family. Further, evolutionary trends of ascoma-types within these lichens and the phylogenetic position of the order Ostropales, to which Graphidaceae sensu lato belongs has been studied. Several transitions from apothecial to perithecial ascoma-types were identified within Ostropomycetidae based on ancestral character reconstructions and maximum-likelihood based methods. The classification within thelotremoid Graphidaceae was also addressed: based on molecular data, a revised generic concept was developed for the Thelotrema clade with the description of additional genera. Further, progress in the understanding of major clades in the Ocellularia clade has been made. At the species level, molecular phylogenies helped to identify subtle morphological characters to distinguish distinct lineages within the genus Thelotrema.
Log in to add this item to your schedule
1 - The Field Museum, Department of Botany, 1400 S. Lake Shore Dr., Chicago, IL, 60605, USA
2 - The Field Museum, Department of Botany, 1400 S. Lake Shore Dr, Chicago, , IL, 60605, USA
3 - University of Minnesota, Department of Plant Biology and Bell Museum of Natural History, 1445 Gortner Ave, St. Paul, MN, 55108, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Ballroom 2/Cliff Lodge - Level B
Date: Tuesday, July 28th, 2009
Time: 2:15 PM