Trypethelium variolosum

Spores of this species averaged 21.5-24x7.2um. They do not stain in iodide treatments (many species within the genus Graphis, for instance, stain distinctly purple in iodine) and number 8 per ascus. All of this information including shape and number of cells is useful in accurately identifying some lichens to the species level. But many can be identified quite reliably either visually or with simple tests in the field.