A division of plants, formerly ranked as the class Hepaticae, characterized by a combination of features. The capsule is usually ovoid or spherical and does not have a lid; when ripe, it usually splits into 4 ‘valves’ to release the spores. A tubular perianth often surrounds the developing capsule. The seta is colourless and semi-transparent; it lengthens after the capsule has reached its full size, and is structurally much weaker than a moss seta. Liverworts may be ‘thallose’, i.e. flattened and showing no differentiation into stem and leaves (Anthoceratales, Marchantiales, and Metzgeriales), or ‘leafy’ (Jungermanniales), with leaves normally arranged in 2 or 3 distinct ranks. The leaves never have a thickened nerve or midrib, and are often lobed or segmented. Typically the thallus is attached to a substrate by means of unicellular rhizoids. Liverworts are found in a variety of habitats, particularly in moist conditions.
Subjects: Plant Sciences and Forestry.