IS THE PACIFIC AN AREA OF SPECIATION FOR SOME FOLIOSE GENERA OF THE LICHEN FAMILY PHYSCIACEAE?

Abstract

  Speciation in lichens is poorly known, as the nature of the sexual reproduction is equivocal and there is no support from fossil lichens. Using examples from the Physciaceae, criteria for speciation in lichens are discussed. Some of the genera are well-developed in the Pacific, and for Phaeophyscia the taxonomy and world distribution is presented and correlated with presumed speciation processes. The genus Physconia, which is represented by a larger number of species in the northern Pacific than in other parts of the world, is discussed and compared with the presence in other areas. In the southern Pacific the genus Physcia is fairly well-developed and evidence for areas of speciation is presented.