Special Interest Group Meeting

An overview on hidden diversity in lichens: Parmeliaceae

P.K. Divakar*¹, P. Cubas¹, O. Blanco¹, R. Del Prado¹, J. Núñez-Zapata¹, B. Roca-
Valiente¹, H.T. Lumbsch², A. Crespo¹; ¹Departamento de Biologia Vegetal II, Facultad de Farmacia, Universidad, Complutense de Madrid, Madrid 28040 Spain; ²Department of Botany, The Field Museum, 1400 S. Lake Shore Drive, Chicago IL 60605, USA

The advent of rapid DNA sequencing has given a tool for detecting and differentiating morphologically similar species. Here, we synthesize the literature on cryptic and sibling species in Parmeliaceae and discuss trends in their discovery. We argue whether cryptic species are more common in particular taxonomic groups, or species with different reproductive modes, and distribution area. Asexual morphospecies show frequently large and continuous distribution while fertile species have usually more restricted or disjunct distribution. Recent molecular studies proved that both kinds of species include several cryptic species. In relation with reproductive modes of the morphospecies the occurrence of cryptic species is more or less frequent. Parmelia saxatilis, one of the oldest species described in the family (Linnaeus 1753), is a good example of vegetative isidiate species that includes many cryptic species having each of them a precise restricted distribution. Flavoparmelia caperata is an example of vegetative sorediate species that includes very few cryptic lineages. Sexually reproducing species having disjunct distribution show different pattern. For example, Parmelina quercina and Melanelixia glabra show disjunct distribution between North America and Eurasia but in recent molecular study populations from both continents were found to have genetically distinct species.

In most of cases cryptic species have distinctive characters but frequently they are difficult to observe and or unexplored. Morphological chemical, ecological and geographical features are here re-evaluated. Micromorphological and sexual feature, and geography were found more suitable to corroborate the phylgenetic lineages.

Classic ‘species pair’ are apparently the contrary phenomenon to cryptic species recognition. Different molecular methods used in species circumscription show that both members of the pair are not different genetic lineages in apothecia vs. soredia cases. However, this hypothesis can not be generalized for apothecia vs isidia species.