Considerations on the definition of epicortex

Abstract

The species of the family Parmeliaceae can be divided into two major groups according to the presence of pseudocyphellae or pored epicortex. In the first group of species the upper cortex is composed of exposed hyphae and in the second group is characterized by hyphae covered by a thin epicortex layer composed of polysaccharides. The presence and type of epicortex is considered a constant character in level of genus and section, and useful in the taxonomy of the family. However, through studies by different authors, in light microscopy and scanning electron microscopy added to the chemical analysis, the concepts of epicortex have changed over the time, according to opinions of experts in the area and these concepts are presented and discussed here.