The second major work of Johann Hedwig who contributed enormously to our understanding of the life history and reproduction of mosses. Before Hedwig, little was known about the sexual reproduction of mosses as is obvious from Linnaeus' name for them - Crytogamia ("plants of the hidden marriage").

Nissen does not call for coloured plates although Pritzel suggests that copies were available both coloured and uncoloured. The plates may well have been coloured by Capieux himself as the first plate of each part bears the manuscript note "et nativ. colorib. expres:" under his engraved imprint.