Mosses, or byrophytes, are categorized into three classes: peat mosses (Sphagnopsida), granite mosses (Andreaopsida), and true mosses (Bryopsida or Musci). Mosses used to be classified as three classes of a single phylum, Bryophyta. Modern texts, however, now assign each class to its own phylum: mosses (Bryophyta), liverworts (Hepatophyta), and hornworts (Anthoceraphyta). This reflects the current taxonomic wisdom that the liverworts and hornworts are more primitive and only distantly related to mosses and other plants.