Liverworts, hornworts and mosses form a group of simple plants called bryophytes (2). Bryophytes lack many of the more complex structures of the higher plants, such as a vascular system, and flowers. They do not have roots, instead they have structures called 'rhizoids' which absorb water and anchor the plant to the substrate. In liverworts these rhizoids each consist of a single elongated cell (3).
Bryophytes have an interesting life cycle consisting of two main parts, called the gametophyte and sporophyte generations, the gametophyte stage is dominant (4). Plants that are in the gametophyte stage can reproduce sexually. Male organs (antheridia) produce antherozoids which move to the female organs (archegonia). Fertilisation occurs and a 'sporophyte' develops, this structure remains attached to the plant. The sporophyte releases spores which disperse and develop into a new plant (4).
This species tends to grow in summer, and sporophytes are only rarely produced (2). Some UK populations appear to consist of just one sex, so spores cannot be produced; this may cause problems with dispersal and colonisation (2).
All liverworts are so named because the lobed types were thought to resemble the liver. During Medieval times, common belief held that the appearance of a plant indicated which part of the human body it could cure; liverworts were thought to cure liver ailments (5).