An order of thallose liverworts in which the thallus is generally flat and ribbon-like, and branched by simple, regular forking. The upper surface is green. Within the thallus are air chambers (areolae) which open to the surface via pores that may or may not be visible to the naked eye. Rhizoids on the lower surface attach the plant to a substrate and absorb water and mineral salts. Members of the Marchantiales are found mainly in damp habitats on a variety of substrates.
Subjects: Plant Sciences and Forestry.