Threatened species of Hepatophyta

Liverworts take on one of two general forms: Jungermanniidea are leafy, like moss; Marchantiopsida are leaf-like (thalloid). The leafy liverworts look very much like mosses and, in fact, are difficult to tell apart when only gametophytes are present. The "leaves," however, are simpler than moss and do not have a midrib (costa). The leaf-like (thalloid) liverworts are, on the whole, more substantial and easier to find than their leafy counterparts.

Liverworts, hornworts and mosses used to be classified as classes of a single phylum, Bryophyta. Modern texts, however, now assign each to its own phylum. This reflects the current taxonomic wisdom that the liverworts and hornworts are more primitive and only distantly related to mosses and other plants.