: Lichens in genus Peltigera are often very beautiful. They have large foliose thalli with deep colors when moist. Sometimes they form very large patches on ground, rocks or wood, which may have more than 50 cm across. Particularly the green ones are very conspicuous. There are 15 species of this genus known in Slovenia (Ref.6). When thali are not well developed, or sterile, without apothecia, or dry their determination to species level may not be an easy task.