Nonvascular plant (with no ‘veins’ to carry water and food), related to hornworts and mosses; it is found growing in damp places. (Class Hepaticae, order Bryophyta.)
The plant exists in two different reproductive forms, sexual and asexual, which appear alternately (see alternation of generations). The main sexual form consists of a plant body, or thallus, which may be flat, green, and lobed like a small leaf, or leafy and mosslike. The asexual, spore-bearing form is smaller, typically parasitic on the thallus, and produces a capsule from which spores are scattered.
First land plants US molecular botanists analysed the mitochondrial DNA of 352 land plants and concluded 1998 that liverworts were the first land plants to evolve, possibly around 475 million years ago.
About 290 species are found in Britain.