The lichen group of plants becomes an undesirable element for the cultural properties of human civilization, disfiguring particularly rock or stone monuments, buildings, carvings on wood, and even on glass etc. Several species of <i>Endocarpon</i>, <i>Peltula</i>, <i>Phylliscum</i>, <i>Zahlbrucknerella</i> are known to grow on lime plaster of old and neglected buildings, including thousands of temples and other monuments built with granite, micaschistose rock, or even sandstone. According to the author, no action can possibly be taken for their elimination. It may, however, be true that any remedy will have to be repeated at frequent intervals, unless some repellent is discovered.