Although algology deals with a large group of plants, widespread and of a great morphological diversity, the history of this branch of botany is fairly young. Linnaeus (1753) listed in his Species Plantarum under the heading “Cryptogamia—Algae” only five genera of plants which are still accepted as algae at the present time. Under the same heading he also described a number of liverworts, lichens and sponges and a few other things.